A friend of the family had a case typical and he grew up as having asperger a branch of autism, however this boy was not intelligent, but you said your son is smart, so I would recommend a professional help because 5 years old is still very early to fully diagnose him.
I would also be more patient - even suffer a little with him - rather than to put him on pills, because this is the automatic way pdocs work, and it will be a pity at his age. Being a mother one must be brave. in our religion it is said "the paradise is at the footstep of the mother" meaning as her son to enter it you must bow in consent or courtesy at her legs so to speak. so it's your duty unfortunately. when one chooses to have a baby, one doesn't expect him to be 100% healthy. God helps you.
seek a professional help and take more than one opinion and don't rush matters . You never know
Child psychologist has my vote as well. They can at the very least steer you to the correct medical professional for further evaluations and get you some answers and help.
I have an autistic son with aggression problems, but (JMO) the other symptoms would have shown up before 5.
Just a tip that's worked for behavioral issues on the autism board I help run/also for both my kids:
I know in behavioral therapy (ABA - which I use for my completely typical daughter and autistic son) they make use of reward charts. You start out in a way you know they can succeed and move up. So you'd reward him/give a sticker for not wetting his pants for xx minutes, then move up to all day. You can use it for behaviors (you get a sticker for acting appropriately whenever)... then once he has # stickers he gets a reward (computer time, toy, something HIGHLY desired that you ONLY give him for this).
Good luck. My son goes in phases where he, too, is a ticking time bomb. It ***** to live on the edge of that - I know how stressful it is.
I hope you get answers soon.
You don't say what kind of repetive habits, but I just wanted to mention that those can be a symptom of disorders on the autism spectrum and OCD. I agree with taking him to a child psychologist.
Perhaps there is nothing wrong WITH your son... but without a doubt, something is very, very wrong!
I don't think this particular forum will meet your needs but here, you will always find people who are empathetic and compassionate. It sounds like you're at your wit's end and I can sense your distress and exhaustion. I would strongly urge you to seek GOOD professional help for you as well as your son.
Sending you sunshine and prayers.
You're son could just be a normal kid with lots of emotions that he's sill not sure how to controll, but here's a link with some interesting stuff about Oppositional Defiant Disorder (ODD). I dont know your son but I'm sure if you read it you could tell right away if that sounds like him or not. hope it helps: http://www.klis.com/chandler/pamphlet/oddcd/oddcdpamphlet.htm