Is that the same guy again?

You already reached out many times by different methods, he isn’t responding. If a person refuses to talk to you, I strongly suggest that you leave him alone.

If neither of you wants friendship or contact, and he is very clear about it in his words and actions, there is no reason to make amends especially since he isn’t interested in communication with you.

I’d also not diagnose people as dismissive or avoidant. Sometimes people just aren’t interested. I hope you are seeing a therapist to help you with these urges to keep contacting people who are not interested.

You are wasting your time. I suggest you look for new friendships and relationships with people who want the same as you. Don’t force yourself on people. Don’t pursue this man please as it’s just a waste of your energy