cheating and staying

my boyfriend cheated on me a few months ago and i recently found out he got a dating app at that time all while convincing me not to break up with him and telling me he loves me. it’s been a month since i found out and i still think about it everyday and don’t understand how he could do it to me. he’s also lied about many little things and i’ll never know the full truth about things he tells me. i love him so much and don’t want him to be out of my life which is why it’s so hard to break up with him and why i’ve never gone through with it before. i want to trust him and believe things can get better but it sucks thinking about what he did while at the same time we get into little fights and he’s not a good communicator over text which is a very easy fix. i don’t know if breaking up with him or staying with him is worse i really don’t know what to do.