I think my long term bf is a cheater and always will be
Why do you think he is a cheater?
Because he is just a bad example of a human being that can't keep his pants on
If you're so sure he is cheating then you should break up with him. You shouldn't put up with someone who constantly cheats.
I don't want to break up with him because I can get lonely at times/
I think that you should still break up. It is better to be lonely than to be with someone who is unfaithful. You can find someone else more worth your time.