What is pro ana and mia?

i know that they are both an eating disorder but what are they exactly? like you starve yourself in anorexia and you make yourself throw up when your bulimic so what do you do when your pro ana/pro mia? i dont know whats wrong with me. sometimes i can eat just fine and then other days i feel like im going to be sick if i eat, like just thinking about food sometimes makes me gag. its the feeling you get when your really nervous about something. like when you first start dating a guy and your all jittery and nervous all the time. i have nothing to be nervous about tho. i also haven't been sleeping worth a crap.. so can anyone tell me what pro ana and mia is and also kind of diagnose what is wrong with me? please only answer if you know what you're talking about.