I've felt the same Rob. To broken to be fixed, what did I turn into, what have I done, I can't let go of the hurt I caused, how do I let go of that hurt.
First is realizing that we're not so unique that we can find and get help. And that's evident just by all the above posts of people who have felt the same. Second, we start by not repeating those actions, don't do those things today.
It wasn't who we were or are that did that stuff, it's what we were. Active addicts. And no, that doesn't make it ok, but that's the "why".
Then we need to talk to others, and work on forgiving ourselves, and learning the difference between then and now. There comes a time for apologizing, but now isn't it. Often, early on, when the hurt is big and we want to try to make things right, we give out way more info than we're ready to deal with, or others are ready to hear, and can cause more hurt, on both sides, than we're trying to alleviate.
Are you that same person today? If not, give yourself a break.