hi miragex, it really might be wise to consult a therapist on how to end things with this woman so she is safe. i rather doubt prolonging things with her will be helpful to either one of you. you may very well get sucked back into the relationship because you obviously care about her, and she will do everything she can to keep you including continued threats of suicide. i am not a professional, but you may want to read a bit about borderline personality disorder to see if she is exhibiting a lot of the symptoms. those who do (and others) tend to have a lot of black and white thinking, and i'm guessing would not be able to see continued contact as anything but hope for the relationship to resume. actually, most women would probably think that imo. that would just be setting her up for more problems and possibly more suicide attempts. i know you don't want that. if someone threatens suicide then call 911 immediately, or their psychiatrist or their parents. there is no way you can be the one to help her because you are the one she is currently traumatized over. as others have said this is a long-standing problem for her.

telling your wife would be in your own best interest as your girlfriend may very well threaten to tell your wife herself. chances are it is probably going to come out either from her or people finding out at work. if your wife hears it from you first, then you have a much better chance at saving your marriage. if she finds out from this woman or someone else then it will be that much worse.

also, i think it's strange that it was her lying to you that caused you to break up with her. it may be possible you are projecting your lying to your wife about cheating onto this young woman in an effort to resolve this problem, i.e. you are punishing her for lying by breaking it off with her because you are afraid of what will happen with your wife by lying to her. also, it would be good to look at why you thought you could save/fix this woman. that is being a rescuer and not healthy. you may be avoiding dealing with your own issues by trying to become involved with someone else's (this is co-dependency and some of us are good at it) or needing some excitement/drama at the prospect of becoming a father and being further tied down to a family.

i do hope you're able to resolve this and save your marriage. you know what the right thing is to do. now you just need to gather your courage and do it. you can't manage this just as you couldn't manage her problems because you don't have control over others. no one does. you do love your wife and child, so now be the man your wife married and a good father to your baby girl.