What are some of your PTSD triggers?

I am six months into therapy and thought I had a decent handle on things but the last 4 months, and especially the last 6 weeks, I have been on a constant roller coaster and crashed last night. I’m pretty new to Reddit and this group and reading some of these posts realize I have triggers I’m not even aware of yet. No wonder I’m so constantly exhausted. I am interested in what triggers others. Abandonment is huge for me. All it takes is for my best friend to not text me back or initiate contact and I’m in a spiral.