Should I have sent this apology?

Hey, I sent a friend an apology today, and I’m worried that they’ll be mad because it’s too much or unnecessary, this is what I sent:
I know you’re busy so read this when you’re not:

I’ve been thinking about sending this like the entire week, and I feel I should.

I’m really sorry about last year. I wasn’t a good friend at all and I am wholeheartedly and truly sorry. I know I apologize too much and all the time, and it’s something I’m trying to work on. But this isn’t one of those. I wasn’t great last year. I often just threw all my shit on you without asking, and that was wrong and rude of me to do. I want to genuinely say, I’m sorry.

And thank you for reaching out. I still don’t fully know why but I’m happy you did. You were a good friend, and I wasn’t, so thank you for giving me a second chance.

Was this too much? I know it’s probably not, but I worry a lot, if it was what should I have taken out? Or added if it was too little?

Edit:
Realized I didn’t add context when I should have. Last year we were really good friends, and we always talked, and some of it included mental health which I struggle with. Sometimes she’d ask what was wrong, and others I just was like “hey can I talk about sornting” and she’d say “sure” and I’d just go for it. Last year in August she said she didn’t want to be friends with me anymore, but would be friendly, then about 2 months ago after a jazz band competition she texted me and we’re now friends again. I sent that as I’ve been having a rough week and just felt that I needed to send that to her. Hopefully that adds more context, if you need anymore or clarification just ask.