Has anyone wrote a letter to their ex?

I was seeing a guy for awhile and my friend who is not my friend anymore broke our relationship up by telling him to block me and stop talking to me (for the second time) .

He did and he said it was because of the drama .

I saw him on Instagram and messaged him he replied but when I said I missed him he blocked me .

On Facebook he unfriended me

The thing is he was right about my friends and trying to please everyone and now that I’m in a low place I want to reach out to him telling him that I’m sorry and that he was right I shouldn’t have put so much emphasis on what my friends think.

He still has me blocked and I don’t want to seem crazy if I send him a letter but it’s been on my mind