Should I dump my live-in boyfriend of 8 years?

It has gotten to the point where we don't even sleep in the same bed. He doesn't want to have sex with me, and I particularly don't want to have sex with him either. I still care tremendously for him, but I think the spark has completely gone. I can't even picture being without him, though. He will not go to therapy because it costs money. We're on a very tight budget. I just don't know what to do anymore. I feel lonely being with him, but I think I would miss him a lot if I left him. I almost told him last week that I was going to move back home for a while, just so I could clear my head a little, and he almost got teary eyed, yet.....he is always sneaking around Facebook & singles websites, and constantly looks at other women in my presence. I have gotten so insecure with myself, because of his rejection of me, that I don't even fix myself up anymore. I am a fairy attractive 37 year old woman, and I still have looks, but I think I am just in a depression. He never wants me to dress up though. He put all my high heels in a box outside, and now I live in flip flops. I could write a million other things, but I just want to see the response I get. Any other women going through this too?