Could something be wrong with my ears; if i go more then 3 ft down while swimming there is a lot of painful pressure in my head.?

This is normal: The water above you presses on your ear drums, creating the painful pressure you're describing. You need to equalize the pressure with something like a valsalva maneuver. Scuba divers do this to depths of 400 ft and more.

May be sinuses: May be normal, but may be congestion in the eustachian tubes connecting ears, nose, throat; may be sinus issues. Might want to get checked by md.

Yes: Yoy may have fluid behind your ear drum or you may have a thin ear drum that with the pressure of the water causes your ear to hurt. Have you had this previously? Perhaps you need to get a good ear exam and perhaps a tympanometry (measure of the middle ear pressure). This could be done either by your pcp or by an ent. There may be other reasons as well. How is yoiur hearing?