Fear of abandonment is the big thing I have (its really severe) and what leads me to believe I have some BPD stuff I need to work on.

About your student, I don't know what to say. Kids often express illness traits a bit differently than adults I hear. I did some very strange things at 15 during what I believe was my first manic episode. If you are concerned with the students behavior, can you discuss it with their parent? I don't believe you are allowed to talk of possible diagnosis, but maybe just mention the behaviors you notice.

I had a friend once who used to set up my fears of abandonment just by saying she was going to leave her husband all the time. My fears would ping everytime she would have an argument with him. Same thing happens if my parents fight and I'm 41 years old and shouldn't still be having this stuff with my parents.