I think I understand you. Maybe not fully but a little bit. I've had a similar time when I was going through some shits and couldn't bring myself to tell any soul. My best friend included.
I simply told myself that I would get over it, no need to burden others with my headache but the more I tried to deal with it, the more it stole my peace.

You do have a valid reason on why you would love to go back to those years and never let go of that one friend you were lucky to have.
Thanks for the tag ☺️.