Embarred and Nervous?

I am trying to become a Vol. Fire & EMT. I been trying since Nov. but they keep messing things up. Well finally, i got a interview which was yesterday. I thought i did a good job, but my sis was in there with me, which i didnt want but they like dragged us both in the room. They didnt have my app. cause the girl with it, her mom is in hosp. So it was 4 people there interviewing me and with long pauses. When i got home my other sister kept asking me how it went and etc. and when i told her some things she mocked me and was like why you say that? They asked me in the beginning something where i answered "Because my family was always in the hospital, i was always around that kind of stuff, etc" (Not exact words) and then almost same ques. i said "I think of FF and EMT as heroes and if could be considered one.." blah blah. Sis said i was quiet & mumbled.My sisters made me feel embarred and now i dont think i want to do it..Now i feel like i did a bad job and am afraid i wont be voted in