What makes a good life? (Can I complain here?)

Let it be known, I write this from a melancholy mental state where my youth blurs my logic. It is somewhat devious the way life takes you through different periods of happiness, sadness, emptiness, you get the point. The only thing anybody can ever seem to say is "that's just life" or something along these lines. It's a lesson learned with time I think, but it may be one of the most difficult things to grasp. I felt really happy recently with this cute girl I met. I cut off all other girls interested in me. I was definitely starting to feel attached to this girl which isn't common for me. Yesterday, she tells me her EX called and they're thinking of patching things up. When we had sex she told me she didn't want to just "fuck" me but make "love". Then she tells me this shit on the way home from the beach. That hurts but it really shouldn't. I told myself not to get attached and to just have sex with her. I'm just mad at myself for allowing such a thing. I don't want anybody saying sorry or anything lmao I'm fine. It's just hard to believe life does this to you sometimes. I literally had a girl who really liked me and wanted to be serious with me. Only for me to tell her I was with somebody else now, she didn't take kindly to that, as you'd imagine. Then this happens one week later, karma's a bitch. I know it is fine and I can find plenty of girls but I just really liked this girl, and she did me so dirty. It's hard to go from seeing somebody almost every night to not seeing them at all. I wish I didn't let myself catch feelings, my trust is so fucked up, especially because I already had issues from past relationships. Time to move on, focus on myself/school and chase a bag. That's the good thing about being young I've got time. Anyways I just wanted to ask what you guys think makes a good life?

Do not get emotionally involved except to your life partner when you get married. Upto that point, just go with the flow ...