I cant see skins or heads

Since i first got Minecraft everything was ok but i couldn't see skins or heads, not even mine.

I tried erase it and downloading it again but nothing happen, i played once in my friends account and i could see skins there, so that means something is wrong with my account i guess. The thing is since i saw some people with there skins and some heads too, when i went back to my account i saw the skins and heads that i saw with her account.

I really wish you can fix this some how, i really don't care i will still play the game no matter what but i think it will be better if i knew what i was seeing and didn't have to ask my friend what it is.

-Thank you for your help