Sometimes parents like you describe, slowly matriculate out or sometimes through patience on your part, find the point that they can give.
It's not easy when the non custodial parent struggles with addiction. It's even tougher being the sober parent in a rather sobering scenario. It's hard to move past the notion of what is loving a child. It's in their own capacity, albeit not at a desireable level to your own standards.
I hope that your solicitor has advise.