My advice would be that you not make any decisions right away.
You have time to decide. You really do. You can stay put while you decide, or you can go elsewhere to decide, or ask him to leave temporarily while you decide. There’s no rush, though. The fact is that you can decide to try, and still can leave at any point in the future if you change your mind.
One thing I know is that at this stage of things, it is very likely that you don’t have all of the information you need. You don’t yet have a timeline of events from him, which can help. You may not have all the information on whether or not he has had other affairs, either.
You may want him to do a therapeutic disclosure, where a counselor assists in him writing out a full and complete admission, and reads it you you in a controlled setting.
You may need time to go through his emails and texts and calls.
There are a million reasons to delay a decision.