If the discovery of the affair is recent, you probably aren't even at a place to be able to answer that question right now. You need time to determine whether or not both of you are willing to invest yourselves in the building of a healthy marriage. I usually encourage couples to wait 6 to 12 months before even discussing the divorce option.
Consider everything that you've got invested in your marriage, including children. Consider the personal and financial costs of a divorce. Consider the possibility for a better partnership than you had before, if you both are willing to work toward healing.
But remember this... you are only 1/2 of the equation. If your spouse, despite what they say they want, makes no real effort, your marriage remains in trouble. You cannot do this on your own. In fact, at some point, you will need your spouse to take the lead in the restoration process so that you can heal and learn to trust again. In some cases, the affair spouse isn't ready to assume this responsibility soon after the discovery of the affair. But if months have gone by and you are still doing all or most of the work, then you're probably working too hard and making it too easy for your spouse to avoid the changes he/she needs to make.
