Meredith
I see that you have a lot of replies but no one answered your question. Jonny Cash is a perfect example how paralegals behave in an Imm law firm, they do some applications for INS and then they think they are as good as the lawyers and (in jonny's case better than the lawyer..

) Leaving personal egos of posters aside.
I would suggest you get a lawyer for your Violence Against Women Act (VAWA) application. This is the only remedy against asshole USC , who think they can control their immigrant spouses just caz of the INS. But before you go to the lawyer you need to make your case so the lawyer will take it and not screw you around as a lot of them just want your money.
First, you need to prove that you have suffered b/c of this mental condition, there is nothing in the law that says that injury has to be physical, it can be mental. Thus , you need to go to a shrink and talk to him as it is having an effect on you, get his report which shows you suffered, affidavits from USC friends that know both of you and can testify he is abusive.
Second, You need to prove he has a mental condition that has gone out of hand and he has sought medical treatment and may not be able to control himself all the time. As for his claim that his medical records are confidential under the privacy laws, well, since you are his wife you have a right to see them. I really don’t know what relations you have with his doctor but since he is mentally unstable he can give you a copy without disclosing it to him else ask your lawyer he may find a better way.
Third, you need to have evidence that shows you entered the marriage in good faith. Also if you pay for his medical or medicine keep records of that too.
Dear, the Violence Against Women Act (VAWA) application is independent of your pending GC and your hubby will never know you are doing this and they will tell you the result independent of your pending GC application.
Good Luck.
Disclaimer: This in not legal advice , just opinions, follow them after you have consulted your attorney.