Theres a number of reasons why you aren't feeling anything. Size makes a difference.. maybe its too small?
Maybe its the position you are doing it in?
Try doing the cowgirl position. Its when the guy lays on his back and you straddle him with both legs on either side of his.
Not only does it go deep down into you, it also stimulates most of your spots.
You could also try doggie style but have his penis go into your vagina instead of rectal.
That makes the vagina tightier and he can penetrate deeper and have more control.

i had this problem with my ex you have to do the kegle exercises. i promise you it helps in the matter of weeks. all you have to do is pretend your stopping the flow of your urine. you are squeezing your muscles and letting it go. you have to do this let's say 10x's a day everyday. you can do it sitting down, or lying down.
when i stop doing these exercises he knew so you have to keep it up.
and positions like doggy style, straddling him, standing up while your touching your toes, or you lying on your back while your legs are on his shoulders should help also.

I'm also facing the same problem and tried all positions, but it never helped, nybe u need to check with ur gynea