Both our two like rough play at times, they find it hilarious. However our daughter will randomly hit our son though, which she finds funny but he isn't amused.
Our youngest son is almost five, his birthday is this month. He hasn't been diagnosed as higher or lower functioning, only as having an ASD. They put it under this these days, rather than Asperger's and stuff. At this moment in time I wouldn't say he's particularly high functioning but I also wouldn't say he's at the more severe end of the scale, I think because they are so young there's time for things to change so perhaps after he's had help things will be clearer.
We also have an appointment this month the day before your speech & language appointment, I hope it goes well for you
Meltdowns are hard. Both of ours have them daily, our daughter will simply scream and cry, she may bite herself or hit others as well. A cuddle usually calms her down but it takes a while.
Our son will launch himself to the floor, kick, scream, shout (which becomes slightly embarrassing when he shouts "GET OFF ME" because I'm paranoid people will assume I'm abducting him or something!), I have had to carry him outstretched screaming his head off on plenty of occasions. Sometimes I will sit with him, be it at home or in the middle of a shop, until he calms down. Sometimes I have to leave him alone, sometimes a cuddle will do the trick, sometimes a distraction like my phone will instantly snap him out of it and this is the case with our daughter as well. They love watching their favourite CBeebies show on YouTube and they also love Talking Tom. Oh and touch is something with our son - he loves having his back or soles of his feet stroked, and sometimes this will calm him down. We also have a dog who helps too.
I don't know if you have heard of autism dogs? The waiting list is monumental but it's worth looking into as they can do wonders for autistic children and adults, many a time autistic children can find it easier to bond to animals than people. We don't have an autism dog, we researched into various breeds and chose the breed we felt suited us best and have been training her. We hope to at some point train her to do specific things to help bring them out of meltdowns.
I can't stand people staring. We have had people give us filthy looks on so many occasions and I do tend to be fairly vocal about this. I usually do say something to those who do this, along the lines of it isn't their fault, they are autistic, or haven't you seen an autistic child have a meltdown before? Or, if you don't like it, **** off, which I shouldn't say but sometimes I have become so angry with these ignorant people. This has happened literally once or twice, I do try to contain my rage at them. It is incredibly frustrating though, knowing it is purely ignorance and if they were to listen to you, they may be slightly more understanding