Love of my life wants to either end it all or become friends with benefits

Like the title states. My boyfriend and I were more than fine. When we met each other we were head over heels and I told everyone I knew that I met the person I was gonna marry and it was the first time I've ever felt that way for anyone. We were together for 3 months, but one day he did a complete 180, he said he wasn't over his ex, and that he fell out of love with me. He knew his ex for 4 years as a friend and they dated for 4 months. I've been trying to make it work, in fact I've been trying to make it work 2 months after our 3 month relationship. I have a lot of patience, but I get easily depressed, too, and this whole situation has made me suicidal for so long. I get migraines, my chest hurts, and I want to throw up from the sadness all the time. He says he can't do anything about his feelings. He's emotionally unavailable and it sucks that I had to figure that out with him, he says. It disgusts him to do anything romantic or lovey dovey with someone who is not his ex, he says. He told me it's either we end it all or become friends with benefits. I don't want to let him go, so of course I chose the latter. But it feels objectifying, and I want to love him so much. I don't know what to do.