I, 27M my accidently didn’t disclose something to my current F26 girlfriend.

This all started on the 4th of July.

I (27M), and (26F) gf were up in the mountains, and i had to run back down to town to get some things. While i was gone my partner went through my phone and saw that i was texting an old friend who i had feelings for, when i was like 15. About 2 years we came back into contact, again all platonic, just catching up… Well last year since the whole friendship was long distance, we thought it would be fun to finally meet, so i went down to visit the friend, and kept it completely
Platonic the whole time. Absolutely no ill intentions at all.

Fast forward we kept in contact, occasional check ins, how’s the family, bullshit like that..

My current partner, is someone who i want to spend the rest of my life with. We met at such a fragile time in my life, and at a point where i was completely done with life.

Anyways, when she found out the messages, and pictures from my trip. She was completely devastated, which I completely understand, and i feel god awful. It’s been eating at her and I everyday, and everyday I continue to stress that she’s the only person i want, and that it was 100% completely platonic.

Yes, i should have told her about this person, she even said if i had of in the beginning of our relationship (4 months) it wouldn’t have been a problem.

I am horrible at wording this, i never thought I’d be having to write something like this.

I fucked up so badly, and what makes it worse is this whole time, she seems good, goofy, all that, but then when night hits it’s like a completely different person.

I’m not perfect, but I’ve been trying my hardest to make up, and reciprocate that she is the only human i want in my life.

Not sure what to do. Give her space? End it? I just want the woman I knew back. And I can’t imagine the pain she feels right now.