I have asked this question myself. And then one day I realized that if I plunged my hand into scalding water, I would not need to ask anyone how to relieve my pain.
The hard thing is that the water gets "hot" (metaphorically speaking) in life so slowly we don't realize when the situation we are in has become scalding water.
Maybe take a very hard look at the "hot water" you are in and ask yourself how much longer you can stand it and how long it will take before you are at the point of no return.
Ask yourself what you want for yourself and how you might get it (maybe write it out in detail).
And then ask yourself what your life will be like in 2 - 3 years if you stay on the path you've been on. How are you contributing to the challenges before you and what if you keep doing those things?
I think you might find your own answers that way.
And - I have so very much compassion for your plight. Hoping you have or can find some support resources. By the time many of us are fed up, we are also exhausted and without mental, physical or emotional resources for a fight. So now is the time to consolidate your resources, find a way to regain your strength and get very practical about taking responsibility for yourself and your baby rather than hoping an addict will come to your rescue (not a good plan).
And lastly, I hope this is not too harsh, but they call those of us addicted to addicts "co-dependent" because that's what we are - dependent. Dependent on an unreliable source of love and/or support (the addict), which is a recipe for disaster. The antidote is to cultivate independence and personal responsibility. You deserve a good life and are the only one that can find it for yourself.
Some great suggestions from others above... Good Luck