My minecraft wont work!

So one day I tried to change my password because me and my cousin 'shared' an account together and he told me "No its okay, I bought another account, you can keep the main one." So I tried to reset the password the password and email, the log-in worked for straight months, a while after I tried to log in after being logged out (Suspicious at this point) So I tried to log BACK in and the log in didn't work? so I continuously tried and tried for weeks and then I finally went to reset the password and IT STILL didn't work? So then I kept resting and after a while it stopped sending me emails to reset my password and or email. If there is anyway to resolve my problem please contact me ASAP!