I think my online boyfriend is lying to me and not being open

my boyfriend and i have been dating for five months through discord. he lives about 3h away by plane. recently we've been having a lot of ups and downs in our relationship but we manage to talk them out. last night, he said he didn't want to look something up for me because he couldn't trust me. i know when he's being sarcastic or if he's joking but he sounded really serious. we stayed pretty silent afterwards. about 15 minutes later, i had to leave the call because i had to take me dog out and give him food, etc. because i was away for so long, my computer fell asleep and i appeared offline. he dmed me saying that he was worried about me but he couldn't call me back when i was done taking my dog out because he wanted to think about stuff. i went back online and got onto a game as i waited for him. he was online playing the game with a mutual friend of ours. i quickly got off and played something else. my mind started to wander and i kept having the idea of "why would he lie to me?" i really wanted to give him the benefit of the doubt and thought that maybe playing the game with his friend helped him think but now that i'm thinking it over, it sounds so stupid. i really love him and i plan on staying with him as long as i am able to but he doesn't tell me the truth sometimes. maybe i'm just overthinking, but can someone give me a new perspective on this?

I'm also currently in a LDR (about 14 hours by plane 🥲), but we were classmates already so I've met him IRL Honestly, communication is the key to everything. Instead of him thinking on his own, how about talking/thinking it through together? Make a list of the issues you have with each other or with what's happening in your personal lives. You said he didn't trust you, and now you're starting to think the same so there might be something you both aren't telling each other. Thinking about the issues on your own won't get you guys anywhere. It might even cause more problems down the line It's also okay to say sorry first sometimes. You may have said or done something before that he might've found offensive even if you didn't think much of it on your own. (I personally hate apologizing first because I'm pretty stubborn, but I know I can be a total asshole and not realize it) Hope this helps!