Aaaw OP, you cannot carry on like this:
I'm stressed and fed up with this.
I like him but I can't stand this,I was up all night,couldn't sleep.
Today I've been sick all morning worrying.
I don't know what i do wrong when he goes quiet on me.
Very gently & respectfully ... from what you have posted - "he's just not that into you".
You have done NOTHING wrong - he just doesn't see you as someone who he is going to respond to, keep arrangements with, or treat with any courtesy.
There's an old fashioned saying which has served me well over the decades: "If a man wants you - he lets you know".
When it's right it feels easy. Simple. No stress. No head games.
As PP said above - He's showing you who he is...pay attention.
What is also happening is that you are showing him what you are prepared to put up with every time you let him off the hook, allow him to blow & hot & cold, & are always the one to initiate contact.
The only way you are going to regain control & lose the awful stress, sleeplessness & nausea, it to cut him out.
He's not going to change his behaviour.
So change yours.
Have a good hard look at what it might be that allows you to let you believe that the crumbs from this mannerless git's table are enough for you.
Remove yourself from the situation entirely - go cold turkey.
He's not treating you well now, he's not going to treat you well in the future, & the only thing you can do above that is treat yourself better by refusing any further contact with him.
he will tell me about girls chasing him,sharing a bed with a girl but nothing happened,how he nearly caused a divorcee ...
Yeah - this is old hat OP - it's called the "pick me dance".
He's using it to keep you jealous, insecure, & desperate to compete for his attention.
bombarding me with lots of texts then hardly anything ...then I'm chasing him -
Another classic dick move. He's treating you mean to keep you keen. By the way - that's exactly the same as showering you with affection when he does deign to see you,. It's not genuine - it's designed to keep you on the end of his string.
Change your perspective around, & instead of asking "why doesn't he call" ask yourself "why on earth an I hanging around for this rude arsehole?"
Give yourself the gift of dignity, save yourself weeks of heartache, & walk away now with your head high.
Not all men are dicks like this - so stop wasting yourself on one who definitely is.