soul mate

15 years ago I met my best friend and soul mate. We fell in love but didn't get together until 5 years later. We were together 9 years, still very much in love at the end. He went to jail and I was a coward and left. 5 years later he reached out to me and Im still in love with him. He still loves me but when I left I hurt him bad. now he wants nothing more than to be just best friends and soul mates without the romantic relationship. says he doesn't see me like that anymore since I left. everyday I regret leaving him but can't take it back. We have forgiven each other for our past mistakes but this will never be more than friendship because of me. How do I get over this? how do I accept us being just friends when all I want is to be there and hold him? I want to be in his arms again. I never want to lose him again and I can't just let him go entirely but I'm afraid being just friends for the rest of our lives will kill me. How can I get over the hurt and pain and longing for him every time I talk to or think about him? how do I accept being just friends and nothing more?