Your husband needs professional help. I am not sure what influence you have with him, but I think it is imperitive. I agree that he is very unstable emotionally, his emotions way out proportion. The clingyness is very disconcerting. The emotional labileness is the very worrisome.
Suicidal people sometimes take other people with them. And NO spouse thinks it is going to happen (of they would have sought help earlier).
Why is your husband NOT wanting to get professional help? Does he want to keep feeling like he is feeling?

I am very worried about you. A temporary lift in mood is when bad things happen.

desdamona

Arguing with reality is like trying to teach a cat to bark—hopeless. (Byron Katie)