Hopeful74, welcome. This is definitely the one place that no one wants to have the reason to find, but now that you have found us, you will find a caring community who are all here for you. Welcome.
I commend you for your strength in filing for divorce. That was a smart and courageous thing to do. More than anything else, letting your WH know upfront that you refused to be his Plan B, that you refused to allow your WH to have a girlfriend, probably helped to pull the wool from his eyes. People who try to "nice" their WSs back fail. Pretty darn much each and every time. They and their hearts get trampled and their healing is set back and back and back. So he's crying to come back big deal. Do Not Budge one bit. You figure out what YOU need to even consider him being allowed back into your life, and you set your demands and expectations.
Please look in the upper left corner, for a square yellow box, and click on The Healing Library. Read it. Read any post in the first 3-4 pages of this forum that have red targets next to them. This is all knowledge that you will need, written by people who have been there and done that. I guarantee that you WILL survive infidelity. Maybe not with him, but YOU will survive it. We're all here to help you.