Your racing a crit tomorrow, not a 100 mile road race through Death Valley.. Proper hydration is important but you do not need to overdo it.. Make sure to at least carry 1/2 waterbottle with you during the race..
I know you have had some lackluster results lately, but be positive, gets a good nights sleep.. I always make sure to drink a full bottle of Accelerade or whatever you use the morning of the race..
Try keeping towards the front 1/3 of the field, do not get too excited and pull too much.. Finishing with the field and seeing how you fare in the field sprint should be your goals.. Remember most breaks in the lower categories will fail, they usually will be field sprints especially on such a flat course like tomorrow..
GOOD LUCK...