Confused in my relationship, feeling guilty about what I did

I (25F) have been with my partner (26M) for 6 years. This is my first relationship and of course began when we were both young. I’ve made a previous post about it but it had a very rough beginning with me finding out, on numerous occasions over the first year of our relationship, that he had been sexting other women on dating apps, webcams, and talking with his ex. We went to couples therapy at 6 months into our relationship. Even though that happened so long ago, I still am bothered about it, and even called off our November wedding because I wasn’t sure I was true to myself to keep continuing the relationship even though since then there has been no other signs of infidelity.

I stayed in this relationship because I thought that even so, we have a beautiful relationship. I consider him my best friend and we enjoy our time together. It is comfortable and easy. There were problems throughout but I pushed them aside to focus on school. Really looking back I was floating by, I enjoyed us, but even the proposal came to me as a surprise and I said yes because I have always wanted to find my partner and spend my life with someone. It was so easy and felt like it just fell into my lap. I began to realize when we got closer and closer to the wedding, though, that I was over-functioning and carrying the relationship. He admits now that he was very lazy and let me take on all the roles in our relationship – I felt like I was the maid, accountant, planner, mother, and it suffocated us with that on top of our rocky beginning. We broke up at the beginning of September and I called off the wedding but we reconciled shortly after. However… I had been talking with a man online that I met through a game and it quickly became flirty. I told my partner about this and apologized, he forgave me for it.

Being apart from my partner I have been so lonely and hot and cold about us. I’ve been driving my friends crazy about where I stand with my partner and I. It even got to the point that I started talking with the guy I met online about it and he invited me to visit him to get my mind off of things. Of course I was very skeptical and I told him we must PROMISE that it can only be platonic, especially because we were flirting before. He lives 7 hours away in Florida and I was thrilled to have the opportunity to do something for myself, something so out of character. I decided to make the drive to see him and Florida, which I have never visited. I have never done a solo road trip or even stayed in a hotel by myself. I told my sister and that was it. So dangerous but I did the trip and I felt so alive to do something for ME. I did not care about the guy at all, it was very very platonic and I maintained that boundary. I saw him a few hours for two days where he showed me around Florida and then I went back alone to my hotel each night. Nothing happened, not even hand holding, I told him I was not interested at all and just wanted the trip for a chance to do something for myself. I loved my independence and I was so proud of myself for doing this for me!

But now, coming home, I feel so disgusted because of course this is a secret from my partner. I still love him and the trip made me think about how eager he is to make us work out through therapy and extra effort. I know he would be devastated that I drove 7 hours to see a man, even though it was not romantic at all, and I had no intentions for it to be. I consider myself an open book and I am debating whether or not I should tell my partner. I worry that the online guy I met might be upset with me and let the cat out of the bag about it, even though it was nothing. Honestly that possibility is very low but it worries me. Do I tell him? Do I let this go because it was for me and nothing happened anyway? What would you do? Am I a terrible person? I have been struggling so much with everything this past month and I am ready to heal but I don’t know how.
We do have an appointment for couples therapy in a few weeks.

TLDR: In a relationship for 6 years and it is my first relationship. The entirety of our first year my partner cheated (but not physically) many, many times. I have resented him for it ever since and it is a trust issue for me. We have been together for so long because I have floated by and we have a comfortable relationship, I pushed away our problems because I was in school and then found myself in the position where I was about to marry him. Also had big problems between us with me over-functioning and him under-functioning. We were to get married in November but I called it off because I realized I needed more from him and still resented the cheating from six years ago. Reconciled shortly after but we are still apart. We wanted to be exclusive still. I have been incredibly lonely and talking with a guy I met online through a game about it all who invited me to visit him to get my mind off of things. I agreed only if it was platonic as we did have a flirty relationship going on. I went because I realized I hadn’t lived a lot of my life and wanted to do something for myself for a change. The trip was very, very platonic and nothing happened, not even hand holding, no flirting. I told the guy I was not interested in him and just wanted that chance to get away. I was proud of myself for going out on my own for once. I am back home now, though, and feel guilty to keep this a secret from my partner. The trip made me realize how much I love myself and value my partner too. Do I tell my partner that I did this? I feel very guilty just because I met with a man who I flirted with before, even though nothing happened. Am I a terrible person? I want to recover from my hurt and I don’t want to cause anymore hurt but I feel like I may have.