My rheumatologist just prescribed prednisone. Now scared to take it after reading mayo on the side effects?

Duration and dose. There are, indeed, significant side effects to Prednisone usage. The most significant problems occur with higher doses and longer duration of usage. Significant problems with short term usage are rare, but not unheard of. You must also consider the consequences of not taking the medicine and the potential side effects and relative effectiveness of other medications.