5 year old ANXIETY....is this normal?

So it started about 2 weeks before school got out when suddenly Seth just didnt want to go to preschool which he has loved for 2 years now!  He would cry and fight it, and even his teacher said he would be really sad the first little while, say that his stomach hurts (which I think is nervous anxiety cause it happened every day) and get really upset when the class got too loud.  He started to get really weird about playing with friends like he would not go to other people's houses and in social situations he would cling to us instead of running around with the other kids.  Primary became a weekly nightmare of cries and more anxiety about being in primary alone especially if it got loud in there.  There was no reasoning with him at this point, no bribing.  He truly seemed terrified.  So of course I start over analyzing and freaking out that there is something really wrong with him. Did something traumatic happen to him?  Were we spending so much time with youth conference and Dittobug that he was being neglected and this was his way of reaching out for help and comfort?  He kind of has always been upset by loud noises like fireworks or babies crying real loud (which was a problem when Jaq was born) but other than that he didnt really have any signs of austism or anything like that and actually aside from these couple of weeks he is very social a totally normal kid.  So one Sunday after the battle (which by the way if we can get him to stay at school or primary he totally calms down and is just fine within a couple of minutes....its just the separation part), we are subbing in nursery and Cordelle spends an hour looking it up on his ipad (I know, probably shouldnt have been doing that in church but....).  Turns out it seems pretty normal especially if some big changes are happening at home like having a baby (although I still dont buy this as a reason for his sudden change in behavior because Seth is way stoked about EVERY aspect of the baby coming.)  But it gave some great advice about not trying to reason with them, but restoring confidence in their ability to handle these situations.  It said not to bribe them or linger around because then it shows that you are worried about them and their ability to cope in a situation they may not feel comfortable in.  And granted  you know its a safe environment like primary or preschool,  its important for them to develop their own coping mechanisms and realize that just because you are being separated for a time doesnt mean they will leave you permanently.  Anyways there was a lot of good information (if anyone wants the website let me know and I'll have to ask Cordelle where it was) but it all helped me feel a little better but the problem didnt go away immediately.  When we were at home there was this constant concern about where I was all day long.  If I put him in the shower he would make me tell him where I was going to be when he was in the shower.  If I went downstairs he would yell for me and make me tell him where I was going to be after I went downstairs etc.  It was kind of annoying but I understood there was a deeper issue there and I had to try to once again instill in him the confidence that I would never leave him.  So one night after getting drilled with him about exactly where I would be once I left his room I asked him why do you feel like you have to ask me where I am going when I leave you for bed?  And he said, well I just dont know if your going to go downstairs or outside or something and I wont know and I have to look for you.  And i remembered a couple of times this had happened where he got out of bed and Cordelle and I were out in the yard talking about the grass or something and he freaked cause he couldnt find us, or downstairs watching a movie.  Anyways so valid points, but still why the over concern?  I remember once trying to really validate his concern and not just brush it aside so I told him, "Seth I think we need to make a rule.  I get nervous when you go outside without asking and I dont know where you are, so I think that it is only fair that if I go somewhere like outside to water the garden, that I tell you where I am going before I leave so you always know where I am."  He was so excited by this rule.  Like I had finally understood his concern and I really tried to do that everytime I would go to another level of the house or outside and I really think it helped prove to him that I took his concern seriously and wanted him to know that he could trust me to do this for him.  I was praying about it quite a bit one weekend, when I found myself at a yard sale and thinking that I should find something tangible that would help him remember that he was okay and that we would never leave him.  I ended up finding this little leather pouch with a snap on it and all these hooks inside for keys.  They were also selling little polished rocks with hooks on them meant I'm sure for necklaces but I got two not really knowing what I was going to say or what I was going to do with them to try to solve the problem.  I told him I had a surprise for him and all day he was excited to see what I had for him.  It told him it would help him not be so nervous about where we were all the time.  So that night I gave the pouch to him.  I wanted to make up some cool Indian story or something (cause thats what the pouch looked like) about a boy being afraid but then found these magic rocks and wasnt....but the story just wasn't coming. So I found myself telling him that Heavenly Father loved him SO much and when we decided to have kids we had to promise Heavenly Father that we would take care of him.  And once he came to our family we realized that we loved him so much too!  And so each of these rocks that were inside this case represented mom and dad.  And they were to remind him that we would ALWAYS take care of him and make sure he was safe.  And that even though sometimes as he grows up he has to go places alone like to school and primary, we were in charge of keeping him safe and loving him because he as one of Heavenly Fathers children and we promised Him we would take care of you.  Anyways it was simple but turned out much better than the fake Indian story I was going to make up.  He slept with it that night and we even saw it tucked away in his sunday shirt pocket at church the next day.  It was small and cool and I think he liked carrying it around and when asked what each rock stood for he could tell us it was for him to remember mom and dad would always take care of him.  I cant say that the problem went away immediately but it was a big turn around for us.  I made a conscious effort to get him comfortable with playing with friends again and going other places, to instill confidence in him and not to linger in places he might not feel comfortable but that he should.  We still have our 5 minutes before bed where we talk about whatever he wants (usually its starwars or kid stuff like fireworks or airplanes) but every once in awhile I'll sneak in my questions too just to make sure there is no outside influences like bullying or something serious that he's worried about.  So that makes me feel a little bit better.  But really it may have been a stage or something weird but I think he is slowly outgrowing it and hopefully it wont be an issue once kindergarten comes in September.  I'm just so grateful for prayer and the knowledge that God knows our children. And sometimes we dont know how to help them, but He does.