Im worried about my penis, and no not its size. just beloe my penis glans the penis is thin but its very tight?

compared to the rest of the penis which has good girth just below the penis head its very tight, and that means when im erect when i masturbate and my penis glans are hard when the tight foreskin goes over my head too much pressure is put on the head and causes it to deflate very quickly, the shape due to this problem is the bottom of the shaft is thick and continues to be thick but just as its reaching the glans it curves in then out due to it being so tight in that area, what can i do, masturbation doesnt feel good due to this i feel its limiting my ACTUAL size. its so tight in that area that the girth goes from 5 to something like 4.2 to 4.3 in that one area where its too tight and because that goes over my head it causes the head to be tiny also. I know this was long but i am in need of some help and i have found that people on yahoo are very helpful. cheers guys for any answers. :)