Hi everyone, this is my first time posting so sorry if I mess anything up. I'm 28, work nights at a factory in Chiang Mai. My shifts are night-to-morning so sometimes I'm so sleepy my eyes won't even blink, but this thing is weighing on me more than tiredness, honestly.

Short version first. I've been with my boyfriend for 3 years and we've lived together for 2 years in a tiny rented room near the factory. He drives to deliver stuff around the province. We've never really had big fights about work or money, but this situation makes me doubt everything.

Two weeks ago, around 5 a.m., I happened to see his phone because I was looking for a coin in his pocket and accidentally lit up the screen. It showed a LINE chat with a woman I don't know — no profile pic, name didn't ring a bell. The messages were short, like "wanna grab food?" "you free tomorrow?" He replied with a little joke then said he'd get home late and they'd talk later. I didn't like it but I didn't say anything then. I told myself maybe she's a customer or a coworker and tried to think positively.

About a week later, someone who knows people at the same factory messaged me saying they saw my boyfriend go to the morning market at 05:30 with a woman who works at a stall in front of the factory (you know, those made-to-order stalls workers like to go to). They said the woman was riding pillion on his motorcycle into the market, they looked familiar and were talking loudly and laughing. I was shocked because he usually doesn't go to the morning market — if he does he'd tell me or bring home food — but that time he didn't bring any bags or anything.

That day I asked him straight up. He said she was a customer from that stall, he was just helping deliver something and stopped to buy his own stuff. He answered in a calm, quiet way but he avoided my eyes. I felt terrible but I didn't want to blow up and ruin things or make him uncomfortable at home. I want to be someone who trusts, but inside I'm freaking out.

After that I started noticing his behavior changing — like suddenly his phone stays in the box beside him more and he doesn't show it to me like before. Last week he said he'd be working late one night, but then left the room really early in the morning and said he had to deliver far away. I wanted to believe him but I was scared. My head went everywhere — why do I feel like my heart's a trash pile?

One night I was a little tipsy after my shift around 2 a.m. and texted him, "did you come home late last night?" He said he was so tired he just slept and then sent me pictures of the view from the delivery truck and some swapped photos. Seeing those pictures made my chest tighten even more. I admit I've checked his phone multiple times, but I've never found rude messages or inappropriate photos. That's the worst part — there's no proof, just this ambiguous, torturing feeling. My heart races whenever he calls or posts a story.

Some friends told me to stay quiet and wait for the right moment to ask specific questions. Others said to gather evidence and then confront him so he doesn't think it's okay. I'm so confused. I don't want to be an overly jealous person, but I don't want to be deceived either. My heart is loving and scared at the same time and it's more painful than I expected.

I've wondered if I'm overthinking (maybe I really am), but friends saw it with their own eyes so I can't accept it. Some nights I get mad at myself for speaking harshly to him without proof. He was hurt and went quiet for two days. I couldn't sleep because I felt guilty, but I didn't get any answer that made me feel better either. I feel like I'm standing on a glass bridge, looking down at dark shadows, and no one will confirm what's true.

I'd like advice from you all. What should I do — talk to him calmly now, wait until I have clear proof, or if the relationship matters should I give him another chance and trust him? I don't know whether to pressure him or let it go. How can I talk without hurting him too much but still get a clear answer?

Thanks to everyone who read this far. Just writing it made my heart feel a bit lighter. I really want to cry T_T

P.S. If anyone's been through something similar, please share. Keeping it to myself hurts.