I just figured out I’m poly and my current gf is upset over it and has been upset and jealous over me because of a girl I’ve been taking to. She keeps asking me to break up with her if I do like someone else and it’s so confusing
It sounds like your girlfriend understands what she needs and has set clear boundaries for you. You discovered something new about yourself, and she has a right to respond to that in a way that works for her. She doesn’t want to date someone who is poly, and she’s made that clear to you - it sounds like this relationship needs to end.
If I started dating someone and a few years in he decided to get really into free climbing, which is a very dangerous sport, I might realize that I just can’t be with someone who free climbs. If I felt intolerable anxiety every time he engaged with his hobby, I might have to leave the relationship. It’s okay for him to discover new things about himself, but it’s also okay for me to make new choices based on changes in the relationship.
Do your best to make the breakup healthy and amicable, and honor her choices - you’re allowed to have feelings for someone else, but she’s allowed to decide that she can’t be with someone who is having those kinds of feelings. Start reading up on polyamory and get your emotional house in order so you can begin some healthy poly relationships.