Can you rebuild trust once it’s broken?

It’s been almost three years and sometimes I find these major inconsistencies in my boyfriends stories. And they’re not big things but it makes me feel like why would you lie (by omission)??? And over time I feel like it’s slowly broken down my trust in him because sometimes I feel so confused because it’s not necessarily the situation but just the fact that he lied about it. Recently he lied about something big-ish and I just feel like I don’t even have the mental space to overlook it or “work through it”. At the same time everything else in our relationship is good but lying about DUMB things are a major deal breaker and make me question EVERYTHING. Like is it just me??? Am I over reacting??