Sounds like a tough time.
Can you try wrapping him? A muslin wrap would be too small but maybe a single bed sheet or you could go to spotlight and buy some muslin and make one big enough.

Maybe going and buying him a toy that only stays in his bed so he can see it everytime he goes to bed and associates it will sleep time??

Do you express milk? Could you try putting some in a bottle and leaving it in his cot so he can have some when he feels the need to?? Or a bottle just with water in it?

Hope this helps. Good Luck. xx