Therapy will help one day (not today). PP, immediately volunteer at a dog shelter and get puppy cuddles. It will console you and soothe you more than getting drunk, crying with female friends or seeing a therapist - though you should do all the latter three as well!
Dogs first. Trust me. I've been cheated on and I swear it was my dog who kept me sane in the first few days of that awful, awful revelation. I literally kept him in my bed or on the couch with me and sobbed wildly into his coat and he just lay there and let me. And licked my tears off after.
Getting that kind of unconditional love from a dog who thinks you're the best thing ever is what you need.