Not trusting the guy I like?

So I recently got out of a 4 year relationship. I’m over my ex, and now I’ve been going on dates with a new guy. I like him a lot, but I feel like I keep self-sabotaging the relationship. I keep doubting him, and then he gets upset that I don’t trust him. He’s never done anything to betray my trust, but I keep being suspicious of him. Like I accused him of being back on tinder and lying about picking up a coworker from the airport... I thought he lied about picking the coworker up bc I can see his location through Snapchat and I never saw him at the airport. I’m being so possessive and I hate it and he himself has said it’s bullshit.

He says it’s bullshit because he hasn’t done anything wrong and I’m treating him that way.

What can I do to trust him? What can I do to stop doubting him?