Being Ignored

This is still going on, but I really need somewhere to talk about it.
At the moment I feel extremely ignored and abandoned by almost all of my friends. They close me off from the group conversations and we rarely talk anymore. When we do talk it’s all jokes and making fun of each other, and never anything serious like we were last year. Last year, we were all super supportive of each other, confiding in each other and saying how close we could be. Now, we’re a year older, and I feel ostracized from the group while they’re still all really close.
I’ve told them everything. When I say everything, I mean /everything./ There’s so much I’ve told them; they are the people I trusted the most. It hurts to think that they stopped caring and don’t like me anymore.
I have some very serious mental health issues. I would prefer to not state them but it makes it really hard to talk to new people and trust them. When I finally trust them, I trust them for good and treat them with utmost respect. I feel like that might make them feel as though they can just walk all over me. If the person I trusted decides they don’t like me anymore, or acts distant, my entire demeanor with them shifts, and then I hate them. As one would expect it doesn’t fare well with said person, and they decide to leave me for good. It’s happened multiple times and I have abandonment issues because of it.
One friend in particular is one I trusted so much more, and one who is ignoring me the most. The new friends he has were the first to start ignoring me, so I feel as though he could have been influenced by them into not liking me.
This really hurts. I have no idea what to do anymore.
And if you feel like you’re being talked about in this paragraph, rethink every decision you have made in your life and ask yourself where you went wrong. Ask yourself why you feel the need to hurt, and why you don’t care about people who have cared so much about you.