The issue is not that she doesn't believe you love her, the issue is that she is unpleasable, full of self-pity, abusive, and tearing you down at each and every moment of each and every day an that nothing will ever be enough for her. It is easier for an addict to deflect everything onto their partner then having to own up to it and see that THEY are the problem, NOT you partner.
There is nothing that you can do that will make her happy or pleasant to be around. We cannot force people to respect us or to treat us the way we know deep down that we should and deserve be treated. Maybe it is time to really take a look at how you feel right now and what you are getting out of your life together and be honest with yourself about the fact that even if she started to work on herself right this moment (which she is not) that it would still take a very long time for her to even start be capable to love or respect . Just because she is miserable doesn't mean you need to live like that.