Negatv thoughts..insecurities..y ds my mind and my heart says two diff things simultaneously?PLS HELP!?

am doing msc.nutrition and dietetics 1st yr..i get insecure whether i wd perform well in to practicals that is yet to begin..i have 7 days of continuos practicals and on the 8th day i wd be writing my practical exam..same way i wd be writing 4 exams as such..my cles wd begin from 6thmay-6thjune..my insecurities r like..whether i wd perform well or not..get'g tensed cz of summer..think'g about travel'g to and fro by bus..it takes 1/2 hour to 45min from my home..shd wake up early in the morning at 6:30am and wd be busy till 5:00pm..get'g scared that powercuts shd'nt occur in the eve when i have my practical exams and my practical cles going on..first and foremost..am pray'g hard that i must sleep properly all these days.to add on to my woes..i myself is a biggest enemy of myself..when i pray to god regard'g my practical exam and cles that everything shd go on well..negative thoughts keeps play'g in my mind..regard'g my practicals.that makes me all the more insecure again regard'g how will things go on.