This is kind of an every day thing with Brandon--I'm actually surprised this is the *first* major meltdown Owen's had in over a year--Brandon has these on a daily or weekly basis (by the way, if a banana breaks when you peel it, it is then a dirty rotten horrible toxic banana that should never come within 20000 feet of Brandon...if it does, major meltdown will ensue.
What would help is if you were finally able to get him into a place that could help you--nobody should really be doing restraints unless they are properly trained to (I was trained as part of my job, and we learned how many children actually die from restraints that were not done properly--the good news is a mother will usually be able to exert less pressure than what's needed, and many of the deaths come from teachers/care providers that put too much
physical pressure on the child--especially in basket holds and face down prone holds).
Getting him into weekly appointments with a child psychologist/autism expert (Brandon's is a psychologist who created and executes social skills therapy on an individual and group basis, plus a behavior intervention specialist for an assistant). That way, any problem behaviors can be discussed on a weekly basis, and a plan to nip dangerous ones can be developed. I am a behavior specialist and can create behavior plans, but I won't do them on my own child because I find I'm not nearly as objective with him (but if you need some help, email me some of the behaviors Steph and I'll do some functional analyses and come up with a couple things for you to try.
I don't know what the weather was like down there, but today it was over 90 plus extremely humid. We couldn't even take the kids into the pool because the last time we tried in this humidity, Brandon started vomiting an hour after we got to the store following the pool. Their little bodies handle weather differently--he might have just felt very badly. And honestly, as much as it sucks, since there were two of you there at the time, it might have been best for one person to take him home while the other person shopped--it seems like he might have been awfully tired (an almost 5 year old falling asleep in the shopping cart is not that common.
: ), and the combination of being tired, the weather, the stimulation of the grocery store, and his little quirks might have been too much...
That said, I would definitely recommend setting him up with regular appointments with a psychologist that specializes in autism, as well as with a behavior specialist. They'll be able to see certain things that sometimes even parents miss (it's amazing what the psychologist has noticed about Brandon that I just took for granted as "normal behavior" when they were actually signs that something major was going to happen).
Hang in there hon...I'm right there with you. Brandon's in the middle of a week long regression right now, and it sucks. He's started abusing animals, so we're right smack in the middle of "how the $#^@ do you deal with this!" right along with you...