Long post, tl;dr at the bottom. Don't know if this is the correct subreddit, please let me know. Sorry for ambiguous title, let me know a better one so I can improve my posts.

Context: my gf (25f) and me (27m) have been together since her first year of university. I was her first sexual partner, she was my second. She had a bf before me in highschool, but they never had sex.

Let me first sketch the context and then I'll get to my dilemma.

Through the years, a few things happened that pushed my gf in some kind of depression. She went out a lot, drank a lot, slept a lot. Eventually, her mom and me convinced her to go see a therapist, which helped a lot. She got through it a few years ago.

However, during this period of depression, she got drunk once and kissed another guy. She confessed the next day, we got into a fight but I found it in myself to forgive her. She told me that part of her was sad that she never had a truly wild period because she met me so early on and this also influenced her action.

Another thing about my gf is that she can be either really passionate about friends or not at all, and that she easily becomes friends with guys. She always kept me in the loop and told me if she was feeling attracted to other guys. I also sometimes feel attracted to other girls, but we don't act upon it so that's fine. These tight friendships usually only last a couple of months after which they sizzle down, either to regular friendships or to just acquaintances. A few guys are also friends with me who I trust so I am 99% sure nothing happened.

Cue to last year. During the summer, she met a guy while she was on holiday while I had to work. She became tight friends, and when she got home she told me about him. During the next month, she is texting him a lot, which isn't that unusual but every time I glanced at her phone when she was near me, she would turn away or close her phone. I mentioned this to her and she claimed that she doesn't like being checked and that she always does that. I admit that I only noticed it because I was already feeling a bit suspicious, so maybe that part was true.

A week or so, my suspicions had grown a lot and I took the low road: I checked her phone (I know, asshole move). In their texts, he talked about how he loves her and she talked about missing him. She said that she liked him more than she wanted, but that they could never be a couple because she is together with me and she didn't want to give up a 7 year relationship for a fling. I only read a bit since my emotions were acting up, but I am 100% sure they didn't have sex since she told him she doesn't want to. I don't actually know if they kissed, she said no but I don't know if I can trust her. We got into a huge fight, but in the end I decided to let things cool of. The fight came up again and I said that I don't trust her completely anymore, she admitted that she still regrets never having a fling or sex with another man. In the end we decided to split up for 2 months and see where we stand afterwards. Since this is such a big issue for her I don't think we'll get through it if I don't at least let her experience what single life as an adult is like. She told me I am also free to do what I want, it doesn't bother her according to her. I don't have any interest but she sounded sincere at least. I told her I don't know how I'll react and that's a risk she is going to have to take.

We are currently 1 month into the break (insert Ross gif). I am still not trusting her again completely, and I am not sure I ever will. The thing is, I still love her very much and find it hard to imagine life without her. The reason for my trust issues is that I am an insecure person and I am afraid she will either fall really in love with the guy from holiday or find someone else that she loves more than me. I know that can happen with anyone, regardless of context and history, but I can't get over this feeling it seems. I'm trying to, maybe I can someday, but maybe not.

I know I have only told my side of the story. I know I am a quiet person and not very passionate about anything (just who I am, maybe autistic traits but never tested). I do try to show her I love her but she does accuse me of never coming up with or organizing something exciting. I'm not an entrepreneur while she comes from a family of self employed, I just work my job and that's enough for me. I don't really make big plans for the appartment, she usually does. I know this makes me a bit boring while  she is usually in charge of the fun stuff unless it's meeting up with friends, we organize easily in that matter. On the other hand I'm reliable and there for her when she needs me or my help. I mostly put her first when deciding on my schedule or drop plans if she needs me. Bottom line is that we both have our merits and flaws, I don't want to break her down.

WIBTA for waiting for another month hoping I can trust her again or is that unfair to her or to myself? Should I talk to her about this?

Extra: WIBTA for asking her to let me go through their texts again as this could be an easy way to confirm I can trust her?

Sorry for rambling, I'm too close to the situation to think clearly.

Tl;dr gf of 7 years has history of emotional attachment with close guy friends, she developed a crush on the last one. Currently on a break because she hid it and I don't know what happened between them (100% no sex though) which is making it hard to start trusting her again. Might be an asshole for the way I am handling it.