Help with CO-Owned nightmare!!

I currently co-own a home with a friend of mine. We purchased the home with the intent to fix it up and sell it. Well the only one fixing it up is me, and he seems to have no motivation in selling it now. He now has a girlfriend moving in, which I am forcing her to sign a lease agreement to cover what expenses she will have to pay. This was met with anger and resistance by him as well. Also he purchased a dog without asking, which has helped cause more damage. I feel like he is trying to push me out of my own investment, and move in. I told him I was going to have an appraiser come in and do and appraisal to see what the house is worth, and that was met with resistance. I am worried about my credit as well for the last 5 months I've had to dip into savings, as well as borrow money from my brother to cover his end of the mortgage. I cannot afford to have my credit ruined by him!! I was wondering if I want to walk away, and he doesn't, what courses of action can I take.. Both of our names are on the deed, and mortgage. I know there are thing such as novations, and quit claim deeds. I guess I am looking at a good real estate attorney, and getting some help. Anyone have any advice, or know of a good RE attorney in southern NH?