I get you. It's awful and and it hurts. I was recently reminded of how dangerous it is (for me anyway) to even get hopes up about another person. Condensed story is that I reconnected in June with a guy I briefly, casually dated almost 30 yrs ago. He told me he was in the process of divorcing/ leaving his unhappy marriage (red flag there, I know) and moving back to our home state so he could be closer to family. I bought it because I know how his wife was even years ago and I just did NOT ever see him the lying type. So we texted and spoke on the phone and he showed interest and I was interested, and it was fun to talk to him and I thought something good had finally happened to me. HOPE reared it's stupid head. Then he abruptly changed his behavior, demeanor and how he spoke with me and the interest obviously waned from his end -- (not) coincidentally, after he learned more about me and my current life, many health problems, etc. On his wife's social media, pictures of them together, clearly smiling and happy, kept appearing. He'd lied to me, played some sick game with my emotions and my head for the past 4 or 5 mos and I feel so stupid for thinking someone actually was happy to be in touch with me and cared about me, in some kind of way. But instead it all imploded and now we don't talk anymore at all (I technically 'ended' our interaction but I know he was already distancing himself anyway. And he's married anyhow, sooo, not my thing to mess with married guys....)
TLDR: I understand how it feels to be no one's favorite person and to feel rejected and alone. I'm sorry you're feeling that pain too. :(