I likely ruined the life of the woman I've been in love with for 4+ years
Is there a reason behind you doing that?
It's true I have been unfair to her. She told me she was pregnant 3 times and each time it turned out to be a lie
Ruining someone's  life un purpose is wrong regardless of the justification. Just because she's lied to you doesn't make what you did okay. It sounds like you two might be better off if you left?
I won't remove myself from the situation since I still want her.
Relationships with mutual self destruction are unhealthy. Sometimes loving someone means letting them go. Don't you want her to be happy too?