Do you have a lawyer? If not, you need to get one asap.

You need an order for supervised visitation if you think he's suicidal.

You need an order for support.

You need to protect yourself financially so you can take care of your kids.

You need to be protected from any financial funny business that H is doing.

This does not necessarily mean you are giving up on the relationship, but that you are taking steps to protect you and your kids from his current craziness.