Hello, guys

tried to deal with it by myself, but I really need advice. Long story short, had a near perfect LTR for 18 months with this girl. Two weeks ago, I got drunk with a couple friends and ended up kissing another woman. She cried and asked time and space to deal with the situation.

Since then, it's been a week and a half that I simply can't sleep well and that I'm feeling extremely guilty and regretful, and I have never felt so anxious in my entire life.

Whether we end up together again or not, how do I handle these feelings? They're completely consuming me and messing up my work and study

Thank you all in advance