how do you beat a mental block?

Hey guys! I'm thinking about running for VP university affairs at my school however I am incredibly nervous and am scared that no one will vote for me. When i was in high school I ran for student government two years in a row but I never got elected however I am extremely passionate about leadership and advocating for social issues and think this would be an amazing opportunity for me. I am a first year nursing student and really want to make a difference at my school but I have such a large mental block and I am an introvert so this would definitely be outside my comfort zone. However, when I am passionate about something I tend to overcome my fears and do it anyway but for some reason I can't beat this mental block. I have until feb 7 to get 25 signatures so any advice would be very helpful! Please be nice though :)