Should we break up ?

so me and my boyfriend been together for a year and 7 months, he recently cheated on me with a girl that he told me i didn’t have to worry about . he’s cheated prior to this as well but told me it would never happen again and that he’s changed . well turns out he was cheating for 1-2 months before i found out . i tried to leave and he begged me to stay saying he’d never do it again and that i meant everything to him, note he’s told me all this before . what should i do .