I love him and I don't

I'm in an 8 year relationship that started when we were in highschool. I find myself looking for something else. I couldn't even hangout with my friends without feeling guilty not hanging out with him instead. All my free times are for him. It's him I think about all the time while he does what is convenient for him. Now I broke up with him told him all that and now he is begging me to stay that he will change. I accepted it cause I care and still feel for him but I still cant keep the thoughts of me being single and free but I'm scared I'll regret it but the thought is so loud everytime!!