How I can cope better with this?

[Misty9]

Ds is 5.5 and we have had difficulties with his behaviour pretty much since he turned 3. It's really hard to describe but he gets REALLY frustrated incredibly easily and melts down. His main behaviour is to throw himself on the floor and scream/wail, throw things, and lately say insulting and unkind things about whoever is trying to help him. He hates being helped and wants to do everything on his own. We can have hours of this behaviour on repeat and I find it exhausting. Dh is better at remaining calm and talking him down but I just get frustrated and end up shouting :( not good, I know.

He has quite a few sensory sensitivities such as noise and clothing, and lately he seems to love jumping off everything (having been a fairly cautious toddler) and goes through quite manic episodes of behaviour where he can't or won't calm down and sometimes has to be physically stopped from running around. His receptive understanding isn't great but his vocabulary and speech are fine. He rarely makes eye contact but can if strongly encouraged. Oh, and he is incredibly distractable and has to be constantly kept on task if you're talking to him.

He started school last year and we're planning to talk to them soon and try for assessment of any difficulties.

But in the meantime, and no matter what label he may or may not be given, how can I cope with him better? It doesn't help that I'm incredibly stressed at the moment and having to take time off work as a result, but even when I'm more tolerant I find his behaviour exhausting and challenging. Giving him extra cuddles etc does help, but only until the next meltdown 5 minutes later. And if I'm the target of his insults then I find it hard to suddenly forget my own anger whilst he merrily switches back to being fine!