No matter who cheated on whom, but married life after infidelity involves a bumpy ride. Though things can get back to normal, it takes a lot of time to mend the bruised ego, restore the breach of trust and allow each other to love and respect once more. Perhaps the only thing that can get you move in the right step is to unconditionally forgive the errant partner. This in itself is a big step for many husbands where the wife has cheated - and if you think you might not be able to fully come to terms with the deviant behavior of your wife, then getting back with her after infidelity, might be a futile exercise.
As I said, it hardly matters who cheated on whom. The essence of the matter is that obviously there is something missing in the marriage which resulted in infidelity. Therefore your job, if you want to get back into a loving relationship with your wife is to ensure that both of you admit that there is something wrong with the marriage and that both of you put your heads together to find a solution to the shortcomings.
This requires the ability to frankly admit your drawbacks as well as candid admission of the guilt involved in infidelity. Your wife has done something which she should not have done, agreed. But who compelled her to do what she did? It's you and nobody else. While she should take steps not to repeat such actions in future, you on your part should also take care to correct or improve upon your inadequacies.
When your wife admits her guilt, to put the marriage back on tracks, the onus lies with you, to pardon her unconditionally. As both you set out to bridge the existing gaps in the marriage, you need to take care to be extra sensitive to the issue of past infidelity. Ensure that this matter is put way in a locked cupboard, the key to which is lost forever. If you bring this topic up again in your discussions, or cite this instance to take revenge on her at a later day, you are calling an end to your marriage forever.
Finally, you have to remember that your wife is in as much pain (for causing hurt to you as well as to herself) as you are. Therefore, there is no question of trying to put the blame on her for inviting misery into the marriage - you and your shortcomings provoked her and she had fallen prey to temptation. It is really as simple as that. Pardon your loved one, if you truly feel that life would be quite meaningless without her around. The call is yours, completely.