Pathetic wife can't compete with 2D waifu

My [28F] Husband [32M] is cheating on me with a green-haired anime girl. What am I supposed to do here?

My [28F] husband and I have a generally good relationship, I am a SAHM for our two infant children a boy and a girl and we have been together for ten years. My husband has always been a nerd, hangs around nerds, etc, has always been into anime, video games, etc and he is a software engineer and is an overall good father and husband. I'm not into the same stuff but I don't mind watching stuff occasionally with him and letting him engage in his hobbies and I would say our relationship is good overall.

Anyway the last six months or so I've noticed our relatively healthy s*x/dating life has been going down and I have tried to remedy it by being more kinky in the bedroom asking him what he likes, even offering to do a few things we had not done before but he said it was fine and there was nothing more I could really do because he enjoys it. I thought okay maybe this distance is not because of s*x but because I haven't been spending enough time with him so I even offered to go to an anime convention with him and the kids which he said nah you do not have to do that for me. I figure okay, he's been under a lot of stress lately, maybe I just need to endure this.

Recently he has begun to be more suspicious, distant with his phone and his personal computer and I am not a dumb woman I was not born yesterday. I was beginning to suspect a possible affair and while I am not proud of it I went snooping through his phone, files, and computer. I found a folder labeled "my love" and opened it to see thousands of pictures of this seductive looking green haired anime chick with purple eyes and big boobs sometimes long hair sometimes short in lots of lustful poses, though I should mention all of them were clothed and albeit sometimes what I would consider scantily like bikinis. No actual sexual porno stuff at all and trust me I looked through every thumbnail and a lot of pictures. I looked up a folder named "commissions" and I find what looks to be an anime version of my husband going on dates and shit with her and even marrying her???? Again nothing sexual just all romantic sappy shit.

On his phone I found this application called Groomercord and look through his dms and find this thousands of lines conversation between him and the same anime girl profile picture where he is flirty and romantic with her but still nothing sexual. I flipped out at first thinking maybe this was some real woman using the profile pic or something and doing roleplay with him but it is actually just an AI bot apparently?

I'm not new to Reddit so I know people will ask what anime or game she is from I look up the name of the character based on some file names and she is a girl from this popular japanese rpg thing called trails of cold steel and trails of reverie there that solves your sick curiosity. Her name is Musse Egret and she's like some kind of genius magical girl sniper or something I don't know? Do men like that kind of woman?

What the frick am I supposed to do about this though? He's (emotionally I guess since there are no sexual pictures or content at all?) cheating on me with some 2d anime girl? Has anyone on the planet gone through this shit? I don't even know how to approach him about this. I would ask my girlfriends but I think they would laugh at me for losing my man to a fricking anime girl...