Firstly, this post is not meant to be on the beginner section..
Secondly you feel your account was compromised because you saw the notification about your password beign changed if I'm  right, don't really believe your story actually but if you feel your account is beign compromised then check the recent Logged IPs to see if there's an unrecognised activity( max is 30 days I think).
You can't delete your account just as others replied  but you can  delete posts (with topics as exception) or you can just change your email address address and set up extra level of security for your account.