Masterbation Problems / Q's -Suggestions?

I was twelve years old when I first orgasmed, it didn't take much - a little clit action and all was well for me. I'm currently 16 years old , and barely reach anything close to what I call an "orgasm". For me , clitoral stimulation is the fastest and most sure way for me to reach a climax of sorts , though when I use my finger for penetration - for some reason I don't feel the same sensation. This being said, it is extremely hard for me to orgasm when being penetrated , weather it's from my finger or a man's penis. Does anyone have any suggestion or ideas ? I'd love to recieve some guidance .