“When someone shows you who they are believe them; the first time.”
As an oldtimer here, hence the name hehe, I certainly understand how overwhelming it is and a break is good for all of us. That said, it sounds like you may choose divorce and I would encourage you to supplement your support system with the folks in Divorce/Separation...where else can you find 24/7 friends going through it.
But more than that, divorce is a significant emotional event in that person's life. You just don't sign the papers and skip merrily off to the daisys. Well maybe for a day or so until the divorce parties die down. But there are a lot of stages to process, not just the divorce but afterwards. A good piece of dating advice is don't date anyone until they've had their papers for a year, so that gives you an idea of the recuperation time. That and then you're still processing the infidelity. You need to do some personal work to make sure you don't fall into the same kind of a relationship a second time.
So take care during your break, take as little or as long as you need, we'll be here if needed.
― Maya Angelou
To save a marriage, you must be willing to lose the marriage.