If the nights sleeps are still fine - do what you can to get through.

This behaviour in my experience is perfectly normal - especially when they learn to crawl - you would think they would exhaust themselves, but cos they have learned a new trick they keep practising even in their cots which frustrates them.

Yep, the teeth could be bothering him too.

Be kind to both of you, and although tiring, getting him to have some sleep whilst getting through it is better than none and being severely overtired and messing up his night sleep (which I hope is all still fine for you!)