Try Try and Try Again

I had sex when I was 18 years old. I have kept my first and only. I never masturbated per se as a younger girl. I do remember waking up humping my bed or pillow with that funny feeling. I had my first orgasm the second time I had sex. I had my first multiple orgasm shortly after. I am able to have a long series of orgasms from regular sex. My husband forced my hands to explore myself after I had already had great orgasms. I couldn't believe that I was making myself cum. I have masturbated with several vibes. They make me cum but not the kind from a real penis. I have masturbated with a shower head. It makes me cum but not like a real penis. I have tried on SEVERAL occasions to finger myself to orgasm w/o luck. Why can't I do it on my own. I can finger myself to orgasm ONLY after I cum from a real penis. I cannot get past this finger only orgasm.