Hey.uhmm my GF broke up with me and now she's dating who i once thought was a good friend of mine..?

I can't get over the fact that she did that to me, and we were together for almost 2 years, and then she started getting texts from this guy who was a good friend of mine, and they are going out everynight, doing things that we use to do, and she realllly like him alot. I dont wanna love her anymore but i can't help it, and she said there was always a chance we would get back together, but i dont think i want that..i have no desire to do anything now and just sleep alll day and do nothing..DOES ANYONE KNOW HOW I CAN GET OVER BEING HURT AND DEPRESSEED??