I really need advice

My best friend of 14 years (lets call her sarah) confronted me today saying she has feelings for me, and she wants me to break up with my boyfriend. I admit my boyfriend and I’s relationship is not perfect, after 2 years he told me he cheated on me once in the very beguinning of our relationship, the first month (so it wasnt as serious yet) But the thing is, is when he told me what he had done i didnt exactly feel that ‘i hate you’ emotion. i didnt know how to feel, because within those two years we’ve been through so many good times, and we both lost our first baby.

Sarah and our other friend have been telling me almosr everyday to break up with him over what hes done and Sarah tells me i can’t always think of our good times together that i need to focus on the bad because what he’s done is not right (which i totally agree cheating is not an okay thing to do, it just happened so long ago i feel like i have every right to overlook it considering all the good times we’ve been together and the times we were grieving over losing our first kid), and theyve been bombarding me to the point where im so stressed and over whelmed because at this point I feel like if i do break up with him, I know i will be absolutely miserable because i love him and we’re planning our future together. But if I dont im scared i’ll lose my friends. I feel like either way i lose.

My boyfriend makes me incredibly happy, and he does everything to make sure that i am okay, and to make sure that i am well. We fight sometimes but nothing ever major. When i talked to him about what Sarah and my other friend have been telling me, he wanted what was best for me and told me that if that is what i wanted then i should break up with him because i need to take care of myself. When i told sarah that she told me it was a ‘red flag’ that he said that because “no one would be okay with someone breaking up”.. But the thing is, i know he was hurt during that conversation and i know he was only saying that for my benefit. (he literally has no girls in his phone so he’s not doing shady shit)

I’m just really confused because i’ve lost a lot of good friends from my bad relationships, and the thing is i always learn on my own and move on, i dont usually just flat out break up with somebody im happy with at the moment. Sarah keeps saying my boyfriend and I’s relationship wont last but I do see it lasting.. He treats me good, he spoils me, he doesnt abuse me, he doesnt lie. I just dont think it’s necessary to break up with him over something he’s done a couple years ago, especially if we werent exactly serious at that time. We’ve been together for almost 3 years now and i dont want to throw that away. He’s literally my serotonin. am i wrong for thinking that i dont think i should leave him over what happened 2 years ago?