What to do? I feel guilty...?

what you can do is see the way your wife see's things, and understand the things she is into, it wont kill you to try you know, as for this girl you met, i think you should just be her friend don't cheat on your wife, even if you are beginning to feel something for this women just ignore it and stay with your wife, try to understand what you and your wife are bickering about and see a marriage counsellor, the better you understand why you two are fighting the better you can brush it away and see why you to truly love each other.