Struggling with one sentence he messaged another girl

I 41f and my husband 44m have been together for almost 23 years. He has worked away on the mines for the majority of our relationship, I'm a sahm with our 3 children.

In early/mid 2023 his porn watching went from once a week while he was away to watching for hours every night, it didn't take long for it to escalate to sexting women on snapchat after being part of a conversation with his work mates about how easy it is to get nudes from girls on there. In the 8 months to early March 2024 he had messaged and received naked photos from 262 different women on snapchat, I've seen the messages and the photos, all 400 and something photos he was sent by women.

There were thousands of messages, but one message I found that he sent while he was away has devastated me, he would tell them they're hot, call them baby, tell them he loves them, tell them what he wants to do to them, he even said once "I'm married, so I don't get to see sexy ladies anymore" but the one sentence he wrote that has kept me broken was

"I'll be thinking of you while I fk her"

I found that message on the morning of my birthday in 2024 and found that I was at home with our eldest son celebrating his high school graduation when he sent that to the woman while he was away at work.

He's doing wonderful with his recovery, he hasn't watched porn since D-Day in March 2024, he's been honest and open with everything I've asked him and I feel that since he's been clean for the past almost 11 months that I should be able to start to move forward, I think I am but then that sentence comes back into my head constantly and it's ruining me. I don't know how to move forward from those words and I desperately want to, I honestly wish I never downloaded his snap data but I know I can't go back in time. What's done is done, I'm hoping for advice on moving forward and to not think that he's wishing I was someone else when we're intimate. Will it just take more time? Also no I'm not in therapy, we simply can't afford it.

I'm really needing advice here please!

TLDR, My husband said to another woman that he'll be thinking of her when he fks me and I can't get it out of my head.