Doctors, therapy or anyone cannot help you unless you start working on yourself. It is not a physical problem, you are experiencing but it is the longing you wish to complete anyhow, which is now impossible.
Does your wife deserve what you are giving her? I suppose no, you have no right to make her suffer on your account. Few things you need to try out, first stop comparing your wife with others two your sexual partner of the past as you are comparing her with two different persons in two different situations, which is very unfair from your part.
Second, stop expecting same kind of pleasure from your wife, which you had been getting from older women. Let me tell you my experience, I recently got married to a beautiful girl and she is all the way perfect to have sex.
She allows me to fulfill my all the fantasies, give me a blowjob whenever I want, she is ready to have sex in any position I like but I if I compare her to my girlfriend of college time then I am not getting sexual pleasure.
However, my girlfriend was not giving me blowjob, very rigid when came to experience new position but I still think she was the best for me and without any reason that means it is all in my mind not in reality but that does not mean that I should be unfair to my wife who loves me a lot.
I accepted my life and my wife completely and stopped craving to get same pleasure, which I got with my girlfriend from my wife. Therefore, accept the fact that you could not go back in the past and get what you want.
Even if you now have a chance to have sex with your aunt I do not think you will be able to enjoy her sexually as if you did. Move on and focus on present life, stop trying to see anyone as you do not have any problem just stop expecting same pleasure from your wife, treat her as an individual.