I need help breaking up with someone

I’ve been with this person a while and it’s been hard for me to do it. Things have really not been going well and I just want to be done but he’s getting really desperate to really talk to me because he’s getting the idea that I’m not happy, he tried calling me from not only his phone, but his brother and his friend number. It’s one of the reason I want to leave it’s getting to be too much and he’s been doing too much. Even right now he wants me to talk to him and it’s Father’s Day and I’m trying to visit my dad at the cemetery. Now he wants to meet face to face to talk but I don’t want to because he’s going to make me feel bad and then I won’t have the will to actually leave. Idk why I can’t just leave he already has another life and he should be focused on that and let me go so I can live my life. I’m 25 I got my whole life ahead of me and I just want to work and go to school and go out here and there without having to answer to someone because it feels like I have to answer to someone anytime I miss a call or two.