Time heals nothing. It is what you do with the time that matters.
Remember that it is better to be healthy alone than sick with someone else.
If your partner wants back in, he/she will have to earn his/her way back into the relationship. Renegotiate the relationship in a way that works for both of you.
There comes a point in time where you may have to draw a line and say, "That's it, I'm done. I'm not mad at you. I withdraw my feelings, I withdraw my emotions. You just go do whatever you're going to do because I'm not going to live like this anymore." Don't stay together for the children. Remember, kids would rather be from a broken home than live in one. They're much better off with one well-adjusted, happy, thriving parent, than they are with two who are cheating, lying, fighting, and living with stress and pressure.
Source: http://drphil.com/articles/article/16/