Assumption of loan post divorce

My ex husband and I separated in Nov of 2011. I still lived at my primary residence with him until April 2012 when I moved to our jointly owned beach trailer until August 2012. During the time I left my primary residence, my ex husband changed the locks and I obtained an apartment. My name is still on the primary residence. He wants to assume the loan, but is self-employed and doesn't look good on paper and hasn't since we bought the house in 1997. I have always been the primary income for all loans and such including the primary mortgage, every refi thereafter etc. I now have a different job and don't make as much as I did for the last 5-8 years but it is still a decent amount and more than he can show as income. He has had the mortgage company send him the assumption application 30 days ago and hasn't turned it in to them yet. I contacted them today. He was late on the last mortgage payment and we have never been late or not paid, ever. The mortgage company will not send me the application as well, until he has been denied, IF he does get denied. I don't know how we find out how much equity is in the house currently to decipher how much he will have to pay me if/when I do sign the loan over to him. Does an appraisal have to be done? Anyway, I just want one of us to get the house and neither of us want to sell it. I know the assumption process takes time 90-120 days after one of us has been approved. Why can I not apply for the assumption at the same time? I would think the mortgage company would want to go with who has what they need to take over the loan. We have not filed for property division and neither of us have an attorney. All assets are individually in our names except for the mortgage and the beach trailer which is paid off and is seasonal. Any advice would be helpful.