Honestly, I'm not a doctor, but it could be Bipolar, BPD, MDD... anything.

You'll need to talk to a professional to get an accurate diagnosis.

I always tell people to see a psychologist for an intake. If you can't do that for whatever reason, then at least see a therapist.

I myself started off by seeing a therapist, who eventually referred me to a psychiatrist and a psychologist.

While therapists usually can't diagnose, they have enough experience treating mental disorders that they at least have an idea of what's going on.