How do you handle attachment?:(

I hate that every time someone I like or is really close to me (not in the form of friends) I can't handle that he has another life apart from me, I feel that he is going to forget me or that he is ignoring me or I am simply too obsessed with that person. I have improved my attachment a lot over the years, but in the end when I really want to commit to someone or be friends with someone I like I feel extremely displaced and it's not even the other person's fault, it's mine, and in the end I end up blocking or moving away from the person, I regret it and I look for it and that circle continues:( I don't know how to break it, recently it happened to me with someone I seriously hate to lose, with all my soul, but he has distanced himself from that game. And now I feel ashamed of myself, I don't want it to continue happening to me in the future, I don't want to feel like an idiot and walk away every time 😭 in therapy I've advanced a lot better than before but it's still very difficult for me. How do you handle that?

I usually have the urge to say "I hate the way you are with me" and then block, then come back and promise that I won't do it again, talk and again feel ignored or about to be abandoned, even I would get tired of myself but I really want to change that little by little. Any tip is good!!!!