Long distance relationship is for the birds

My husband and I live 2.5 hrs away from each other. Having different households to maintain. That's how it was when we met although he mislead me to believe that he'd buy a home where I live. But that was over 2 yrs ago and there seems to be a million excuse as to why we cant live together... mostly economical reasons but also because I have a 15 yr old son and he said that he wants to wait for my son to graduate high school in 3 yrs before he'd consider living with me. He is kind to my son and very helpful to comment or give advice on raising a young boy but he refuses to live in a house with someone else's son and does not want to assume responsibility as a father to my son although my son has a relationship with his own father. When I attempt to discuss our situation and that I am unhappy, I get all kinds of excuses as to why we cant live together. His excuses vary and there are so many. I'm wondering why I am even married to a man who cannot commit physically or emotionally? I was recently diagnosed with MS and need my health insurance so now that's another reason he is using. It's true that the medicine is incredibly expensive but I am just frustrated at it now being used as another excuse for his not wanting to be here. Oh and the lovely thing is that we barely even have any communication, about 1 hr total a week. We see each other on average about 1 or twice a month for the weekends. I wonder whether he's cheating as I have my own unmet desires. I just shut my cell phone off for the night. Why bother to wait for his dumb 5 minute call to ask me how my day went and hope he doesnt fall asleep when I open my mouth. He is a workaholic and I knew that from the get, but I wasnt expecting to be put on the back burner. He knew how to rope me in by saying how he just wanted to spend "quality time" with me and drove here almost every weekend. Yah, I fell in love with a man who slowly became unavailable in every possible way.