Hi hun - I'm so sorry you are going through this.
I see this is your first post - the just found out thread is often particularly helpful when you first arrive. You may want to look there.
Welcome to SI - you will find this is a great place to get support.
The healing library in yellow box on the top left has really helpful information.
I would seriously doubt your husband is telling you all the truth. Most WS (wayward spouse) seem to minimise things. Often things related to when the affair started, or how long, what was involved, when it stopped, protection and how many they have had.
The accusing you of affairs can be deflecting behaviour and could be a sign that this isn't his first affair.
I would suggest you go and get a STD screen to be on the safe side. Don't be embarrassed, doctors have sadly heard it all before.
Are you and he going for counselling? Is he in NC (no contact) with the OW? Does she have a boyfriend and does he know?
Both separately and at some time in the future marriage counselling.
Whether you can reconcile will depend on lots of things but if you want to and he is truly remorseful the are lots of couples here who are examples of how it is done.
Life will be a roller - coaster of emotions for a while yet.
Here are some thread links for you that may be helpful.
The one below is more for the WS but do read. I printed it out and gave it to my husband. I needed him to understand that this wasn't going to be something I was going to be "over" in a few weeks. More like 2 -5 years.
Also "How to help your spouse heal from your affair" by Linda MacDonald is a helpful book - it is really short ( a few hours read) available on kindle.
Hang in there. Lots of hugs.