cant login on the right account after updating

I have a problem, I tried everything I could do, changing passwords, searching for other information. I can't log in into my account, I haven't changed anything to it, not even a password, I know my email is correct and I know what my username is or was but I fill the correct information in but it says that or the password of the mail is wrong and this all happened after updating my Minecraft if I login into the minecraft.net site then I get logged in into what looks like someone else account but with my email, my name was Gunnlaugr but now it is STARGAMES_SG and my skin changed and i don't know what to do. but still my account has in the launcher all the skins i pasted in there and my versions i had, so only the name and skin changed