Lost trust

My boyfriend and I have been together for almost a year (long distance). This past year, he has been caught flirting with another girl on Instagram (someone from his school) and he had downloaded tik tok videos of half naked girls which he saved. He also mostly followed TikTok half naked girls. Since then, he’s deleted Instagram and TikTok but now whenever we don’t talk or it’s been a long time since we talked, I feel that he’s talking to someone else because when he was texting that girl he said the reason was that he didn’t know how to talk to me and so he had reached out to her because I was in a bad mood and he didn’t know how to talk to me and so he decided talk to someone else. So now whenever he goes on a trip or we don’t talk for a long time (we usually FaceTime or text throughout the day or call to fall asleep together at night) I feel like he’s talking to someone else and with all that happening, I feel like he doesn’t love me and I know he’s trying his hardest but I don’t know how I can trust him again. I don’t know what to do so any advice would be helpful right now.