Been reading tons of stuff about relationship blues on the net and there are just all kinds of trouble in relationships out there. Cheating is the main problem. If your partner cheats on you that is a sure sign you are with the wrong partner, no one should put up with that for one second, if you do forgive your partner, which you should do so it doesn`t eat you up, you still have to end the relationship because it will not be the last time your partner cheats on you. If you waste years on a cheating partner and then decide to put an end to it you will have wasted all those years which you can never replace. Life is short and to spend your time and energy with someone that doesn`t respect your relationship only hurts you not the one who is cheating, they could care less about you.
Going thru a breakup with a cheating partner is hard, but in the long run it will pay off, you will be able to spend your time looking for a partner that respects you like you deserve. You have to be able to enjoy your own company to get out of a bad relationship, keep busy doing positive things in your life and soon you will find the partner that will be with you til the end, keep in touch.