Repairing your relationship after cheating may be next to impossible. You must really have an incredibly forgiving person in order for you to fix your broken relationship. You will both need to be willing to do whatever is needed and commit to the relationship completely. There can be no poking it with a stick or it simply will not work.
Many couples who agree that the relationship is worth saving will make their first step to seek the help of a marriage counselor. This is a great idea. The two of you are emotionally challenged right now and may not be able to think as clearly about the whole situation as you should. Having an objective third party available to moderate the process might really help the two of you get ahead.
It is important for both of you to understand that there is no excuse for infidelity, but nothing happens in a vacuum either. While you should never condone cheating it is often just a sign that there are other underlying problems in the relationship. Figuring out what those underlying problems are and finding constructive ways to deal with them may be the answer to moving on after your guy steps out on you.
Who knows, dealing with the underlying problems may be a way to make your relationship stronger than it has been in a long time or maybe even better than it has ever been. You just have to get over this crevasse to find that out.
Of course, if the one who was unfaithful has cheated before and this is a long standing pattern of behavior rather than a one time moment of weakness, the odds of ever having a trust-filled relationship with him are slim to none.
This may sound harsh, but the truth is the truth. If the person you are in a relationship with has shown through their actions that they are so insecure that they feel they have to habitually cheat on you, do not think that they are just going to turn over a new leaf and be the person you want them to be, do not kid yourself, it does not happen that way.
If you are in a relationship with this type of person you really would be wise to cut your losses and move on before they cause you anymore pain. Someone who is so fundamentally flawed can never be a worthy partner and you deserve better, everyone does.
If you decide that you simply can not forgive your him, whichever the case may be, then you will have no choice but to try to move on. Be willing to give it time and if it was you that did the cheating, make some much needed changes.
Moving on after adultery is a slow going process whether you decide to try to work things out or just cut your losses and move on. Nothing is going to happen quickly and it will not happen with out some pain, but it can happen. Just keep your dignity intact and prepare yourself for the battle of your life.