I am finding myself scared to death

This is going to be one of the first actual type jobs i am doing in over 5 years... I was fired from my last job for who i was related to after 18 months working there, and was never actually even given a chance to earn the job for myself, a task which i wanted badly. Once that happened i lost all confidence and this idea of beginning a job even a temp one as this is, is so daunting to me, my heart is a tight ball and i feel i could drop dead at any second from fear alone....