I CANT UPLOAD MY OWN SKIN!!!!!!

OK so here's my story when I try to play mine craft 1.11.2 I want to upload my skin since I saw that my own wasn't uploaded so I uploaded it. And when I played one of the maps I downloaded I noticed that it was a Alex default skin not my own so I quit the game and I re upload and then i noticed that then I did it said none chosen I tied to logout nothing happened it still kept saying that non was chosen I even deleted the game it still said none was chosen like really plz help me PLZ!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!