I suggest you read the book Cheating in a Nutshell by Wayne and Tamara Mitchell. They write at length about the requirements for reconciliation and difficulties involved.
Personally, I don't see how you could ever trust her again. Dude, life is hard. Shit happens. Your spouse is someone that you must have 100% trust in. You literally put your health and your wealth in that person's hands. I don't think you truly understand how intertwined married couple's lives become. Untangling those lives after a few years is very difficult and very painful.
I don't think you ever "get over" the betrayal. As has been pointed out already, your intuition is good and it's important to listen to it. You're scared of another betrayal because it's statistically very very likely to happen again.
I had a hard time sleeping for a long time as well. Are you able to see a doctor? My doctor gave me anxiety meds so I could sleep and it was such a big help. Going through the grief and trauma and also being sleep deprived is just awful.
Check out these podcasts on this page. They're very helpful and validating.
I also highly recommend checking out the book Cheating in a Nutshell, and Why Does He Do That?.
I've been separated from my husband for 6 months now (I found out about everything over the entire year of 2020, bit by bit). It was really rough at first, especially going through with making him leave, but it gets better.
This is not likely to change. Please read these books asap (you should be able to read them free on the Libby app):
Cheating in a Nutshell by Wayne and Tamara Mitchell
Leave a Cheater, Gain a Life by Tracy Schorn
Why Does He Do That? by Lundy Bancroft
Living & Loving After Betrayal by Steven Stosny
And listen to these podcasts. These are super validating and will help you. Cheating, especially ongoing serial cheating, is abuse and very unlikely to change.
I recently left my husband after discovering he'd been cheating on me nearly our whole marriage (12 years), and cheated even before we were married. I know how you're feeling and I know how difficult this is. I'm sorry you're going through it 🖤 Don't let there be a 4th time.