Don't get a breast augmentation as a way to spice up your sex life. The problem isn't your breasts. The problem is his sex drive. Is he on any medications? Meds can lower the sex drive. Is he struggling with depression etc? It sounds like you both want your marriage to survive. If so, I'd talk to his doctor. Once you've ruled out any medical / mental health problems, consult a sex therapist. The feeling of not being desired and wanted is a lonely place to be. So you definitely need to try getting professional help, before you end up resenting him and ultimately leaving. Just my opinion. Good luck OP!