Never put in your head that they are "better", they have nothing over you, they are human, you are human. Good mentality will beat a "better" opponent. Good basics will also beat a "better" opponent and don't get sloppy or make mistakes because they will know how to punish you for them since they are "better".

It sounds to me like you are still looking for a "silver bullet". There aren't any. Learning a new move takes time and repetition, something you do not have between now and Wednesday.
What have you already got in your arsenal? What can you hone to a razor's edge? Take one move from each situation, for example: outside single, stand-up, spiral ride, rebar tilt. Make them as polished and refined as you can. Then go into the match with the mind-set that you have the tools you need. If you can REALLY hit thost moves there are very few wrestlers than can beat you.

You may not be able to speed up your learning curve or experience, but you can make every effort to be in better shape than anyone you wrestle. It was said by either Dan Gable or J Robinson (I've heard it attributed to both) that the first two periods are won on technique, but the third period is won on heart. If you can hang with a superior opponent and wear him out, you may be able to beat him with better conditioning.