I know nobody can diagnose on the internet but since I was about 16 I have suffered on and off throughout my life and been diagnosed on and off with both depressive disorder and Generalised Anxiety Disorder and I have been medicated on and off for these things too. I am now mid 40's and currently taking SSRI's.
When I first experienced it as a teen it was frightening as I knew I didn't feel right but didn't understand why, I just felt very low.
I also remember suffering a panic attack after my sibling was playing really loud music.
At the time I was really scared and didn't know what was happening. I now understand these and how to help myself if they ever happen. Fortunately I'm not experiencing these currently as I'm medicated.
I have had periods of not being on medication where I have been ok but usually it comes round again after a few years or trauma and then I end up on them again.
I could go on about various other things but just wondered if it can start out like this? Depression and anxiety as a teen.