There is this guy, he claims that I am his future wife, but I don't want him because God told me that he is not the one. I told him, but he doesn't want to accept that. I used to visit him, but one day he demanded sex from me and I told him that I can't do that. But one day he roughly touched me sexually. The first time I didn't like it but I had no choice because he is too strong for me. This happened repeatedly.
Yesterday it was worse because he had anal sex with me. I told him that he must stop but he didn't stop. Afterward I felt guilty, empty, useless, a loser and a failure. What I want is to go back to my position that God gave me as His child. Now I don't want to see him again, but he is serious and I feel like I might hurt him by saying to him I don't want him anymore. I don't know what to do. All I want is to submit my life back to Jesus.
What you are saying is that he raped you. You should report it to the police. But even if you choose not to, you need to stop seeing him. You should have ended this at the beginning when he first told you that he wanted sex. Worrying about a wicked man's feelings is foolish.
The problem is that you did not follow up your words with action. You said you didn't like him touching you, but you kept going back. He assumed that you don't mean what you say. What he did was absolutely wrong, but he's been ignoring you all this time and you kept coming back.
Therefore, it is time to put what you say into practice. You are guilty for going back when you knew there was danger, but you are not responsible for this rape. Apologize to God for not avoiding evil (I Thessalonians 5:21-22) and then move on with your life without this man.