Everything you are describming very normal and typical. Nothing sounds out of the ordinary. Usually patients will describe the permanent crown as feeling bigger than the temporary crown. Also there should be some pressure on the adjacent teeth once cemented for the proper contact, that will dissapear. Often the tooth will completely fine with the temporary cement and will often be very sensitive once it is removed and the perm. one is put on. The probability of you needing a root canal or having problems is very slight since the your temporary crown was comfortable. That's a good indication all of this is just transient.
All you have to do is buy some time, I would give it at least another 1-2 days and you will notice it feels better and better.
Again from your UC forum dentist, MyUC
39 Year Old Male, Dentist
Dx: Ulcerative Colitis 1996 via colonscopy and biopsy. Pancolitis with chronic and moderate inflammation.
Started UC around 92.
Past Meds: Asacol and occasionally Prednisone
Have had 6 colonscopies throughout my hx with UC.
Current Meds: Imuran, started with 200 mg and recently lowered it to 150 mg
Most recent colonscopy 2009 after 6 months of Imuran, colon is 90% healed
Currently in remission