Maybe you both need some time away from each other?

If you really just want a friendship only with him then keep your clothes on all the time when around him. Be firm that you want friendship only and dont waver.

Time away will allow him time to find someone else that he can have sex with and that will stop his constant pestering of wanting it from you.

What you have is a very dysfunctional relationship on so many levels. Is he really a good "friend" ?

Yes YOU can change yourself, You admit that you have been abused by people "because your a caring person". You can be a caring person but still set boundaries in your life and only do what is comfortable to you.. But only you can stop allowing people to hurt you.

Take care