Cheating Husband-to-Be

I dont even know how to start this. My hands are shaking just typing it.

Im (F27) meant to be getting married in 3 weeks. dress is paid for, flowers sorted, family booked hotels, the lot. and now I just feel like my whole world has just collapsed.

I found out my fiancé (m 28) has been cheating on me. Not with some random, but with one of my bridesmaids.

I wasn’t even snooping, I swear, He left his phone on the sofa when he went for a shower and a message popped up. I dont even know why I looked but I did. It was her name. It wasn’t even subtle. “can’t stop thinking about last night xx”....

I confronted him there and then and he tried to act like I was going crazy, but when i showed him the message he just.. went pale. after hours of arguing he finally admitted it wasn’t just once, it was going on for months last year.

I feel like I can’t breathe. Like this is the person I was meant to trust more than anyone. The person I thought had my back forever and my supposed friend was smiling in my face while sneaking behind my back??

I kicked her out the wedding obv but it doesn’t feel like enough. All my mates are telling me to call it off immediately, my mum says the same. My dad actually said “if you marry him you’re stupid” which broke me even more because i know he’s right.

But then I look at the dress hanging up, I think about all the money spent, the guests, everything we’ve planned, and idk I just freeze. I can’t imagine standing up there and saying vows to him now. I cant imagine looking at wedding pics in 10 years knowing what he did.

I keep wondering if maybe I could forgive, but then i picture them together and it makes me want to vomit. I feel dirty even being in the same house as him rn

Sorry this is such a mess. I just don’t know what to do. Cancel the wedding? Try and work through it? I honestly feel like my life is over.