Other ways to say 'Here I am pouring my heart out' to my best friend
Come clean would work...But you mentioned you want to right your wrongs, so consider
'make amends'
to compensate, as for an injury, loss, or insult
I'd like to add that, although this isn't the Interpersonal Skills stack, you seem to be frustrated with your friend not replying. If you are the one in the wrong, they do not necessarily owe you a response. You might have to practice patience in them replying or even forgiving you.
Good luck