That's really tough... hang in there. I don't think your thought process is wrong - it's natural to miss her regardless because you really care about her even if she's really a mess and has done you wrong.

Also I'm sure it took a lot of strength to cut her off the way you did and it's probably for the best because if you keep letting her get away with it nothing will change. Not to mention that you are trying hard to stay sober and even without the cheating part it would be pretty terrible for you to have to be around drugs/alcohol all the time like that...

Perhaps the quick switch you mention has to do with her entering a severe manic phase, but that's just a guess... you are probably aware of this having been in a relationship with someone who has BP but mania can often result in extremely reckless behavior, drug/alcohol abuse, sexual promiscuity, etc.

I think the addictive personality that results in drug/alcohol addiction could very easy also play a part in being "addicted" to a relationship like you are suggesting.

I think you've made the right decision for the time being... and if you can't live what the things she's already done to you then maybe you shouldn't go back at all even if she gets clean (unless you can really and honestly forgive her for all that she's done). Even mania doesn't excuse away all of it even if that is a contributing factor...

Long ago I was in a relationship where I was mistreated and needed to do what you did, but I didn't and definitely regret not having the strength to do it (I can appreciate how hard it is because I couldn't do it). It sounds like even though it was obviously very tough you did the right thing. She is going to have to make some changes on her own and then seek you out if there's any chance of fixing things (and you should choose not to if you already feel like it's been too damaging to the relationship to ever work again). I definitely wouldn't recommend pursuing her at all or even calling her but that's just me (and of course easier said than done when you're in love).

Most of all don't let all of this drive you back into the addiction that you've already gone through so much to overcome - she may have stomped on your heart but don't let her take your sobriety away from you too. Stay strong and hang in there...