I'm glad. Perhaps you just have a helping personality! There are lots of organizations that can use volunteers, maybe your helpful energy needs to be used somewhere? I really mean that. You are probably a very kind and compassionate person.
Enabling someone is not good for them, or for you, doesn't mean any part of his addiction is your "fault" he will use until he decides he doesn't want to anymore (if ever) and not a moment before.
I know I cant be with him because I cant bring him into my childrens life unless he is sober.
And I'm sure you have discussed this with him. So realistically, he's not getting sober and you can't ever actually move forward in this relationship. I don't know how old your children are but unless you are prepared to wait until they all leave home? It's always important to view a situation like this as it really is, not in a wishful way.
He is a drug addict, he is today and probably will be tomorrow (and a year from now). That is/was your romantic partner. Is that all you need or want in a relationship, someone who can make time for you when he isn't busy using or getting drugs. I don't know what his lifestyle is, how often do you see each other, have you ever known him sober (I suspect not). That's another thing, you have been dating the drugged version of him, you don't actually even know him as a sober person?
Some distance from him would probably be a really good thing for you, to clear your mind and really ponder whether this is good and good enough for you?
Regardless of his reasoning, it's truly not about you, it's about him and whatever he's thinking. That in no way makes you "less than".