illustrator for iPad keeps crashing

Hi, I'm new to using illustrator on iPad.

Just created a new file and has been working fine up until i downloaded some fonts in Creative Cloud to use in illustrator. As soon as i started trying out my new fonts in illustrator, it started to crash nonstop. Now i can't open any files, and because i downloaded a bunch of fonts, i don't know which particular font is causing it to crash. 

Is there a way to figure with font is causing the problem? or do i need to delete all fonts? and if so, how do i delete all fonts at once? 

thank you!