Password problem with logging in on El Cap

I have a MBA and decided yesterday, I had reason to change my usual account login password. I went in to Settings > Users and clicked Change Password. It asked for my old password and then asked me to enter my new password twice. When I clicked Change Password to confirm, I got an error message saying that my old password was incorrect, which it wasn't otherwise I wouldn't have been able to log in. I think I tried once or twice more and then gave up.
When trying to login this morning, it would not accept my old password. So I tried the new password that I had tried to set and it did not work either. So I shut down the computer and rebooted with CMD R thinking that there was an option there to reset the password. Once the computer came back up, I was given a prompt to enter a password. It would not accept my old password. So I entered the new password I was trying to use and it did then log in to the recovery screen. I didn't find an option to set a new password, so I restarted the computer. The account log on screen then came up and I was presented with my Avatar picture. I clicked it and then the computer just logged in without asking for a password.
Anyone know whats going on here? Should I try the change password option again? I believe if the computer goes to sleep, its not going to let me login in again unless I try the CMD R process again.