is it cheating ? or is it worth it ?

Hi girls !!! So me and my fiancée have been together for almost a year now and I love her a lot she really understands me as a person and has patience for me and my family adores her. We live together with my mom and my sisters fiancé we are all one big happy young family (we are all 18-25) I know my mom has her hands full lol. The big problem is our sex life is terrible. I feel no spark/passion with her but she does with me. I can make her have these great orgasms but she can hardly make me cum. She knows how I feel and we kinda came to terms that we will stay together but I would have sex with other people. I don't want to damage our relationship it's not worth it but I feel frustrated I can't live the rest of my life like this either. When this first became a problem early in the relationship I suggested we break up but she said no that we could work it out. Now what ?