anxiety? depression?

So i know i’ve had depression for over a year now, which has made me distant, lose trust, and lost friends. i’m so closed up but that’s okay. but that’s beside the point. sometimes a wave of sadness crashes ontop of me randomly, when i’m with my boyfriend, when i’m showering, or when i’m doing homework, but i’m not sure why? depression? but other times i’m scared for no reason or scenarios that are not very reasonable go through my head and i can’t stop thinking about it. For example a truck crashing into my window but there’s a strong fence outside my window, a murder coming into my house but i live in private apartments with cameras, someone following me but there’s no one behind me. make sense? and there’s time when my heart/chest hurts, like a heavy feeling or as if someone has my heart in their hands and they’re crushing it. What are these things? Do they even mean anything? maybe i’m going crazy..