Need sexually healing

This is my first time posting anything . And I'm happy that I get to share and get some feedback . I've been with my boyfriend for 3 years now but 2 years out of the 3 our sexual experiences hasn't been that great or hasn't been like it use to when we first met . I tried to help guide him through somethings but it's been 2years and still the same . I thought I could love him enough and do without the sex and just focus on our relationship but I don't think I can . I even started self evaluating myself thinking I was the problem, maybe my sex drive isn't like it use to but I'm 28 how possible . Lately I've been talking to this guy and he flirted with me. And I could feel myself already getting aroused, like my body needed to hear that. Furthermore I want to feel that way with my boyfriend but it turns out we aren't there. And I don't want to continue the relationship if the sex isn't good at least , I keep thinking what will happen when we get married . We seem like an old married couple and even they get their groove on 😂. Am I wrong for feeling this way ? Am I wrong if I want to end the relationship ?