It is NOT okay. He is not looking after your interests at all. You said you bought the house together. What does that mean? Are you a co-signer for the mortgage, or is the mortgage only in his name? Are you on the deed, or is the deed in only his name? If you're not sure, dig them out and find out.
If the mortgage is only in his name, YOU ARE NOT RESPONSIBLE FOR IT, and DON'T EVER SIGN ANYTHING SAYING YOU WILL BE. If you do, you will be buying a house for him, and/or whichever (ex) wife gets the house.
In fact, let him go on disability and use that money to pay his bills. You really should not be supporting him. If he is denied social security disability, there's a reason. If his doctors will not fill out the forms, for instance, it's because they don't agree with him that he fits the criteria for being disabled and not able to work.
If he loved you, he would insist on you being on the deed, as a joint tenant with rights of survivorship (JTWROS). Since he is not taking care of you, YOU need to. You need to protect yourself and your own child. Do some role playing, with a friend, or even with your mirror. Practice TELLING him what you want, rather than asking. I need you to add my name to the deed. Here's how to do it--of course, find out so you can tell him. I need for this (______) to happen, etc.
It's okay to trust yourself, and do this for you and your child.
There are two-three other forums that I strongly suggest you start reading. They are at http://community.lawyers.com/forums/
When you scroll down, you see there are forums regarding family law, real estate law,
and trust, wills and estates law. Read for a while, and ask questions there, too.
Ann Landers would say, "Wake up and smell the coffee".