You can't get her back.
I was with my fiance for 5 1/2 years, and in January he confessed to a porn addiction. I has been very clear before we got together i had a hard, red line boundary of i see porn as cheating and wouldn't date him if he wasn't willing to be 100% porn free. He swore no porn, and for the first 3 years of our relationship he led me on to believe he was asexual with no libido for anything sexual, wouldn't even kiss me. Seriously it was like being around a platonic friend, there was no physical affection of any kind. He instigated making the relationship sexual at the 3 year point, acting like he'd finally "come around" to letting sex be a part of his life again.
In January he had a panic attack and told me he'd been wanking to porn twice a week behind my back not only that entire 3 years, but it continued after we started having a sexual relationship, for several months, before he finally "quit for me". He admitted he knew if he'd told me about the addiction when i laid out my boundary i would have "friend zoned" him, so he deliberately disrespected me, my feelings and my boundaries and plotted his lie to get me to be with him.
It has destroyed me, and left me with PTSD. He knew i would never have consented to have sex with him without his lies, that if i knew he'd watched porn even once after we got together it would be instantly over. And he wasn't even on only fans interacting with the women in the porn, paying for it, like you were. I'm willing to bet your wife would not have consented to some/a lot of the rare sex she has gotten out of you if she knew what you'd been doing behind her back. That honestly feels physically violating, it can feel very much like having been sexually assaulted, and have a traumatic emotional impact.
He also rolled out the "I haven't physically cheated" bullshit, believe me, it hurts JUST as much as if you had been putting your dick in another woman. You have chosen specific women, sex chatted with them, paid them for personalised content. That is as sexually intimate as it gets. You HAVE cheated on your wife, repeatedly, and by the sounds of it with more than one woman.
It was "only fantasy" to you, because YOU knew everything that was going on, and were having your wants met. For your wife, it was very much her reality a sexless marriage with a man willing to spend money to talk to, wank over and get personalised content from other women, instead of her. Do you have any idea what you have done to her self esteem? you chose every single one of those porn actresses, multiple times a day, instead of your wife. You chose and began sex chatting and paying for content from multiple specific women, choosing them instead of your wife. What she thought was you having no libido, was you having crazy high libido for any and every woman who wasn't her.
You have betrayed her trust, destroyed her self esteem, cheated, possibly made her feel physically abused if you had sex knowing she'd never have consented if she knew about all this, and you expect her to take you back?
Seriously, how can you think any of what you have done is in any way forgivable? YOU chose all those women over your wife, over your kids, and the fact you have now done all these things to go porn free means you were capable of giving it up years ago, you just didn't want to out of selfishness, because you were getting what you wanted at the expense of your wife. It is only now it has consequences you don't like you've even attempted to change, and it is way too late.
If she's feeling anything like i feel about my ex, she is completely disgusted by you, cannot forgive you, and never wants to be in the same room as you let alone ever be touched by you ever again. I hope for her sake she can get out of the marriage and any financial entanglement and afford to split and live free with her kids seeing as little of you for just hand overs as possible.