When counseling others -- it's wise to remember, that the way we know -- is because we've been there, and done that, too!
And, I'm glad you mentioned that "some work and some don't". All too often, I think we give others the idea that we'll always be sick and a couple that both do the 12 Steps -- still won't work as a healthy relationship.
Happy to announce this isn't true... because we have seen them work for others... even when they haven't worked for ourselves. (Speaking strictly of myself here).
There are some healthy fish in those toxic ponds -- but, consider yourself really lucky -- if the one you fish for -- hasn't already been caught!
Either way, you can continue to try and try and try again, and again, and again -- we know of those who failed w/ their first half-dozen or dozen prospects, but they EVENTUALLY found one that was desperate enough to want what they had to offer!