I wish for you to be well, Stuck1nhead. I will not ask for you to disclose more than you have. With that said, if you are judging the circumstances objectively/reasonably and conclude that she is a "toxic person" in your life, the decision of "when to draw the line" is yours. You might "love her to death and your lives are intertwined" as you say, but there are other factors to consider to which you are probably already aware.

Forgive me for asking such a question that you might have already done... have you tried talking with her about the circumstances to which you are alluding, that concern you and so on? If talking is not an option, a relationship might be difficult to maintain, develop and so forth.