Any tips to help get to sleep?

Lately i have not been able to get to sleep and only surviving on 2 or 3 hours does not help. i go to school 4 days a week and work outside all day in over 100 temp the other 3 days. it usually helps me sleep well. but not lately. i have tried everything i can think of, counting, soothing music, tapping my foot, drinking a glass of milk (lactose intolerant) even laying there for HOURS tonight has been that night. i have been laying here for 5 hours, no music no lights nothing but the humming of my fan (i need it for comfort reasons) idk what else to do and i DO NOT WANT TO TAKE SLEEP AIDS! but im thinking its my last resort, my doctor wants to do a sleep test on me, which makes me nervous. PLEASE HELP! im willing to try anything! ~please no joking around, im tired, and i just wanna sleep~ thank you in advance!