Should I have to be on social media for my job if I am not comfortable with it?

I work at a library as a children's programmer. I do all of the programming for children (as the name infers). I do storytimes, ukulele classes (which is actually for adults and children), teen and middle school game day. I also plan and track down sponsors for our yearly summer reading program (which is national program across America incorporated by CSLP). My boss has been asking a lot of demands from me lately. I also work as a fulltime student a university, and I was working full time here until she finally, but reluctantly reduced my hours. Now, she is requiring me to promote and run our social media sites, which I am not comfortable with. I don't even use social media. And I barely even know how to. She wants me to start posting myself on videos doing book chats for children and singing on the ukulele, and just stuff I don't feel comfortable with. I don't want to be on social media and I never have. And I don't feel like I should have too. But, she is not really giving me much of a choice. What should I do?