I M29, met my Fiancee F26 in 2017 and have been together for 7 years now

we met as kids and made childish mistakes of betrayal and the usual relationship issues on both sides, but there was forgiveness and moving on.

My fiancee didn't have the easiest childhood and was exposed to harsh life at an early age, which I think got me her as she was at the age where one would think she would be swayed by guys promising the world and riches to her after relocating abroad, but she chose me, a simple student at the time who cared genuinely for her and her progress.

We got engaged this year in April, and got married in Denmark (Court wedding), we have already started paying for our main big wedding next year.

Now, last weekend, after a night out, I discovered a message on her phone that showed secrecy, and the previous messages were cleared, the message that came in was a guy asking her about her outing and also giving her "feedback on some dinner date / inviting her over to his place since it won't make a diff".

I got really mad and let my emotions get the best of me at that moment, I have seen quite a number of similar situations during our 7 years of relationship and I couldn't believe I had to still feel this way even while married/planning the big one, I left the wedding planning groups out of anger.

She booked a hotel nearby to stay for 3 days and give me space, she came back home sick and apparently has already checked out of the whole relationship, she has seen this marriage isn't what she wants for herself and she says she has been through so much in life growing up, and that her heart is telling her this isn't the marriage she wants and she isn't even ready yet for this.

I'm in tears as I write this paragraph because I had planned to counsel to also try to understand where the problems we have are hidden, or the psyche behind the problems so I help us out of it.

Yesterday she said she's 80% out and she already sounds done, I have never imagined life without her and I don't know where to start.

This is going to ruin me in a way I'm scared of, I'm scared I don't have the mental makeup to go through this, I love her so much and I'm ready to take any steps to let her trust in us again.

she says this is more on her side, and I've suggested therapy but I have a feeling I'm wasting my time.

I'm lost here and I don't even know what to do