How can i overcome this guilt?

[Shatterer]

I've been with my girlfriend for 14 months now. I cheated once within the first month, which I never told her. Then again after 6 months, which caused me anxiety so severe I told her, which relieved my symptoms. Now after 14 months I woke up one morning, thought sexual thoughts about a random girl (normal for me) but following that I began to collapse in on myself. My anxiety prevented me from eating anything, from thinking straight, and eventually even drove me to ask God for help, despite being a devout atheist. Despite everyone around me telling me that admitting my past faults to my girlfriend would not help, I did it anyway, revealing even my first cheat over a year ago, and other small but non-sexual things I found myself guilty of. Even after admitting this to her, my incredible anxiety persists, preventing me from enjoying anything or eating. Should I go to the hospital? Try to get medication? What should I do?

[Paxiled]

Try therapy.  Might help you not only to learn how to deal with your anxious thinking but also to determine why you do things that make you unhappy, like cheating.