regression

I feel as though yesterday brought back so many feelings and memories, that it as fucked my head up more. I was finally starting to let go of things and move forward but then last night idk. It started off being awkward and then Tas came and didn't acknowledged my existence, which was just rude. Ola then showed up with Toby which was totally fucking awkward. I was feeling so out of place and not in the mood, then I started thinking about him and about Rosa's last party which completely different. How can people go from being so close and then nothing at all. That is three people I've lost. What's wrong with me? I don't intentionally push people away, do I? I value loyalty and if someone is loyal I will respect them and if they are loyal to me then I will one hundred
 percent be behind them with pretty much anything. The problem is that there isn't many fucking half loyal people out there, everyone is just out there for themselves.

The question I have now is how do I know if my depression is coming back? I feel it lingering and I can't stop it. That scares me.