i really don't understand functions

studied functions and variables in high school, hated my life and almost failed. Now struggling with them more than ever at a maths course in college. I never could wrap my head around the concept or the terms/signs used and my own father who is math professor couldn't help me out. I don't want to give up but it's at the point where I find myself crying at a homework question from frustration. is there any course or youtube channel that can benefit me. I'm really desperate here