I Ruined My Marriage Before It Even Started

My fiance just left me and called off the whole wedding. Everything is my fault. I've always had issues with manipulation. I'm being honest.... I have been the type of person who would try anything to get what they want. My fiance has anxiety, so I would use that. I never admitted to myself that I had a manipulation issue until he almost left me the first time, and even after that.... I still didn't want help. I just get frustrated and I want things to go my way. If they don't I get mad and say things. Really bad things. Things that if I told you I've said, honestly you all would probably reach out to Glow to ban me... Today I came home from class and he had his bags packed. I asked where he was going and he said he couldn't do it anymore. Tears started to stream down and I begged. I told him I would change. I even agreed to go to therapy finally. But he said it's too late. He can't mentally handle it anymore. He said I've drained him of any health he had mentally and if he stays and marries me he feels the only way he's gonna be able to get out is by taking his own life.... Hearing that.... That he would rather take his life than stay married to me... Destroyed me. I begged, but he stopped talking and just walked out the door.... I know I have problems, I know I need to change. How can I get him back? He is my life. It was never my intention to hurt him like that. I just have problems.