confused?!

So I love my husband dearly and been together 12+ years with 3 kids. Idk bt having sex with him isn't the same. I don't get aroused, he don't make sure I have an orgasm or realize if I'm enjoying it(of course I'm faking it), bt the only time we have sex is when I'm ovulating because we want another kid. The only bad thing about all of this is that I have the urge to cheat cause I'm not being satisfied. I know if I tell him how I'm feeling he will be mad and start thinking selfish. plz any advice if you have questions or need deeper details I'm more than welcome to express that.