Rather Masturbate Than Have Sex..?

Ok so I've been in a relationship with my boyfriend for almost 5 years. We've been living together for almost 2 years and I really love him. He's a great guy, a prefect gentleman and I want to be his wife someday. We have a pretty good relationship; we hardly ever argue and we enjoy each other's company. The only problem I'm having is that I secretly masturbate to porn🙈 and I'd rather do that than have sex with him😳🙊🙈. I almost never enjoy sex with him and has never orgasmed with him.. Telling him how I truly feel about our sex life will CRUSH his self esteem and I don't want to do that.. What should I do? I tried talking to my doctor about it (I even broke down crying) but she just suggested that I find a "bigger" lover and/or purchase an oral b vibrating toothbrush to stimulate myself with 😠😡. I want to stop watching porn and enjoy sex with him. Is anyone else going through this or has gone through this? I need some advice.