Is Borderline Disorder at Play?

I'm going to try and make this long story as short as I can. First off, I identify as transmasculine/androgynous and non-binary at times. I was born biologically female. All throughout high school I had never dated or even kissed someone, and as a child I don't remember having any crushes really on anyone, at least strong crushes. Once I got out of high school and had gone through much emotional trauma when figuring out my identity and had extreme gender dysphoria, I began to start online dating. I eventually came to accept my body mostly but will always identify as a guy. Online dating has been both wonderful and horrible for me at the same time. Without it, I may still have never kissed anyone at the age of 23. When I found out how wonderful it was to share romantic and sexual intimacy with someone I really liked, I immediately feared abandonment from that person. I'm attractive and am an intellectual, as well as an artist with many interests and talents. Since high school, I have spent so many years looking for a relationship, and of all the years I've spent online dating, none of them have ever really succeeded, or lasted but a few months. Yet each time I was rejected, I noticed myself going through the same cycles, and it was only getting worse. I would get immediately attached only after one date and start to wonder if they have lost interest in me. My anxiety would get bad at times, and I felt the need for them to tell me the truth about how they feel about me, and this was when things would start to turn bad, even if they seemed to like me so much when I was physically with them. It was when I wasn't with them, I couldn't help but wonder. Their lack of response for a long duration when texting, or me as the initiator for most of them was a sure trigger. Each time I began to show some real interest, they would cut me out not long after. I would then resort to self-harm sometimes afterword’s, or have suicidal thoughts, or extreme self-loath.

The final straw happened a couple weeks ago. I had met this guy on tinder, and we hit it off. We had such strong emotions for each other so fast, and I was never treated so special before in my life. The thing was, I was his 16th relationship, his longest had lasted 4 months. Not only that, but he had held 7 or more jobs already at the age of 21 because he couldn't sustain all the prior ones. I had come to find out that he has borderline personality disorder, and in the past had suffered from intense emotional dysregulation, as well inflicting self-harm and suicidal tendencies. Right before our second date, he called me to tell me he had met up with this girl from tinder and things got physical. The eventual result was this poly relationship, in which I never got to meet this girl because she had no interest in meeting me. She wanted to keep their relationship separate. Of course, you can't force an attraction to someone if they don't have it, but I really would have liked to have met her in the very least. Needless to say, this was a good enough trigger for my anxiety to make me wonder how genuine this situation was.

This guy I was seeing had appeared to be doing better and went to group therapy sessions to help with lasting relationships, he had told me to communicate everything with him, as it helps build a stronger lasting relationship. He had told me that he liked us both equally, and that he loved me as a person and cared about me so much, that he always wanted me to be in his life no matter what. The truth was that he was not always true to his word, or he would tell a story explaining that sort of emotion he had experienced as if to fit the mood of the moment, then tweak the wording slightly later in that same story. Whenever it seemed to me that he was lying, his response was that he had changed his mind. I communicated to him like he wanted me to till the very end, all my fears and emotions. And if you can guess, the very thing I thought I was doing so well on, was the very thing that had caused him to breakup with me. He claimed that he was doing this for my own sake and happiness, and he always told me that he would be there for me till I didn't want him anymore. Infact, he very much wanted my friendship, and told me that if I stopped talking to him he would be okay with that, but it would suck a lot, but he mentioned seeing me was like seeing him in his past relationships.

Naturally I was heartbroken and devastated, and I let him know that. The last time he talked to me was through a text saying that he would talk to me the next day and not stop putting effort into our friendship, but also early the next morning I did send an emotional text saying I thought he was making a mistake maybe in doing this among other things. Two weeks went by and nothing, which was fine because I needed to sort out my thoughts and feelings. Truth be told, I'm glad I'm out of that relationship now, and I really did want to be friends with him, so a few days ago I sent him a very well-prepared letter presenting my maturity and acceptance as having as a friend. He never read the letter I sent him because it was a link in which you must ask for permission to access, but I had asked him in the very least to read it. Still yet, no answer, and later that night I told him I was just trying to forgive him and be friends, and that there is/was no ulterior motive. I thanked him for helping to grow stronger as person and I have, and that if he ever needed someone to talk to I could be here. In the end it was me putting forth the effort and wanting to be in his life till he didn't want me anymore.

Despite my imperfections, why did someone who wanted to treat me with such upright respect and have me forever in their lives do what he never said he would do? I have also explored the possibility of me having bpd, and I'm doing what I can to change that now because this situation brought to light what may have been my problem all along. And I understand now you must love and respect yourself before you can do the same for anyone else. Despite me knowing this, it will always hurt me that he ended up treating me this way, and I will never understand fully why he became so cold and different. I have also learned to stop looking for relationships and just try and enjoy my life. Perhaps some of you can help show me a different perspective on this situation or give some advice so I can better myself in the future so that I don’t push people away that I care about anymore. Anyway, thanks for reading this!