I went to my cousin's house a few days ago and I logged in Minecraft from his computer, I want to play on my computer now and I can't login, I changed the password and email and it still doesn't let me log in. I went to his house to see if i was logged out there and I was, it lets me log in on his computer just fine, but when I try logging in from my computer it gets this error:
Sorry! Make sure you are online and try again
If your account was created after November 2012 or if it has been migrated, use your email. Otherwise use your username.