Okay so here's the thing: if your discord says that youre playing minecraft right now, that means one of two things. One, your discord has also been hacked and you should change your password immediately and just for the extra security enable 2-FA. Or two, your computer is just messed up somehow and thinks youre playing Minecraft even though youre not. Try restarting your computer and that SHOULD fix that.
If you wanna cover both, change your password on discord real quick then restart your pc
Edit: wait nvm you said your skin changed and that you cant log in. If your minecraft login had the same password as your discord you should really change your password for discord as soon as possible