My husband[32 M] had an online affair while deployed. Do I [30F] stay with him?

Some context, my husband deployed a year and a half ago, and we have been married for over 5 years. He left me with our 4 month old, 5 pets, and a full time job for this deployment. Not the best but also it’s all shared responsibility for both of us. While he was deployed I did keep some distance as it really hurt me that he still deployed, when he could have likely gotten out of it a number of ways. He returned about 7 months ago and really threw himself into our relationship.

Recently I asked him to work on his ADHD as he has a lot of common issues associated and was diagnosed with it previously. In turn he got prescribed adderal. Then he asked me to go on a work trip with him, and I agreed. Now I’m caring for our toddler and working part time for 2 weeks as a little escape while he works on a big project.

We road tripped down over the weekend and he was acting weird and tweaked out (sorry I can’t think of a nicer way to put it). Then on the first night he stayed out until midnight, after leaving at around 6 am and taking our only vehicle here. I immediately got worried he was abusing his medication as he had done that a lot as a teen.

Here’s where things get extra tricky. He left his personal laptop with us at the Airbnb so the next day while he was working I did some snooping, really just wanted to make sure nothing weird was going on. I don’t go through his stuff ever, but something told me things are weird and I just did it. I found a lot of stuff, some of which I’m chalking up to him just being horny and looking it up. Others not so much, I found that he had made multiple snapchats begging someone to unblock him(I found via email Snapchat account info). Then I noticed that the same account had added these accounts back on Snapchat.Someone named Caroline.

I was shocked at this point and didn’t know what to do. I tried to do nothing but it got the better of me, I downloaded snap on his laptop and logged into one of the accounts long story short she confirmed that they had a relationship and that it was very wish washy, she also covered and said he did not sext her or do weird stuff. They did talk about meeting irl and she did know about me. Also, (thanks to my husband) I know that they did at the minimum sext. I confronted him and he kept lying about what was happening with her, now he’s saying he’s telling the truth and lovebombing me into oblivion etc. I also found that he joined multiple voice/video chats programs which is where he apparently met her. This all started (apparently) while he was deployed. I have no idea how long it continued or if it continued when he got home or if there’s other women, etc. Some of the weird stuff he was looking into was wife cuck and a lot of 3 somes. He was even going through threads talking about “cheating on wife” on Reddit.

I don’t know how to proceed he keeps telling me “I’m yours” your my everything, your beautiful ya da ya da . I worship you. He also wrote out a long note but 90% was focused on just sex. I don’t know what to do, I make as much money as he does and I can get out but it’s like I’m stuck. I don’t know how to get unstuck. Do I stay? Do I just leave and cut my losses? My only motivation to stay is my child and my hate for change.

Sorry for the book my head is a mess right now. I tried and failed to keep it short.

TLDR; husband had online relationship and lied, possibly continues to lie about it and now I just don’t know how to move forward. Do I stay and try to figure it out? Or is this behavior just going to repeat itself?