I was nervous and anxious while having sex for the first time and it made me feel nauseous and i threw up. will the nauseas go away after i am relaxed and not nervous and used to having sex?

Anxiety, not the actual act of sex is most probably the cause of your nausea. As your anxiety fades, your nausea will resolve. Try deep breathing exercises, meditation/prayer, journaling, or other relaxation techniques to help yourself relax/feel less anxious. You may also want to reconsider whether you want to be having sex if you are so anxious about it. Time may help.