Anxiety issues how do i keep myself positive?

been having anxiety issues over clinicals for my ultrasound program, today was the first day and it didn't seem bad at all, it will take time to get used to the hospital and facility i ll be working at... is it normal to feel tense over an event like this? i was actually suppose to start 2 weeks ago but they delayed it until now because of some hospital issues, i got really tense this past weekend coz it was my first day there today being exposed to everything so i lost a lot of sleep, is there any supplements out there to control anxiety besides prescription medication? i can't seem to lose all these negative thoughts in my head and i have trouble sleeping at night, need some advice thanks!