I am a dental nurse. It may just be that the crown feels bigger as your not used to it because its different to what you had there before eg a broken tooth or a filling etc.....the dentist should have checked the occlusion at the time of fitting the crown, I would give it a few days and if it still feels wrong then go back and he can check it again. All he will do is get you to bite down on a peice of thin blue paper so that it marks the tooth to show if you are biting too heavy on a part of the crown then he will drill it down if you are, you wont feel anything though as its not the tooth. hope this helps.
ETA - the crown thickness is normal, it will probably feel like that until your mouth gets used to it, the mouth is very sensitive to these things but you will get used to it and it will eventually feel normal. but the occlusion needs fixing if its not quite right.