I really don't think I could ever trust her again. It's time to shift over to your deeper emotions. I would suggest getting some help in making that shift. The other person's already decided to leave the marriage. With other affairs, though, it's important to do the work of really understanding why there's an affair in your marriage, and do the work of healing.
Healing is individual and as a couple.
When you've done most of that work, you'll know whether you've got a good marriage or if you don't have much to work with. Don't do it automatically. Marriages aren't all bad or all good, and you need to see what's possible with your marriage. An affair presents you with a crisis and in every crisis, there's an opportunity. Make that opportunity work for you.