3 Hour Glucose Test Tomorrow....dreading it!

FirstTimePregnancy

I have to be there at 7am tomorrow for my 3 hr test.  For those of you who have done it, how did you get through it?!  I have heard that you first are on a sugar high but by the end you get very jittery.  Do they make you sit there in the waiting room the entire time?  I have terrible back problems and don't think I will be able to walk after 3 hours of sitting there.  I'm hoping I can go out to my car and recline for awhile to take some of the pressure off.  Please share any tips you might have to help me get through it!  TIA!