Needing Advice...guys r girls?

Okayy soo my girlfriend i'm textin and my ex-girlfriend is outside of my house. i told my girlfriend "brb" and went to see what my ex wants... she said that she wants to get back together...and that made my heart exploded, because I think i still have feelings for her...i told my ex to go home and i'll think about it, she said that she expect one by 4 hours. so i said okayy.. soo now im upstairs thinkin like crazy and my brain hurts... and my stomach is all butterflies.... i remember why i broke up with my old girlfriend... she like cheated on me but for some reason i still love herr... but now girlfriend now is nice and amazing! I love herr so much... and idk who to pick to be in a relationship with... and i am not gonna cheat on her with my former girlfriend....