two login accounts, admin account pw unable to login

I made the mistake of making two accounts- admin account and standard account after upgrading to Yosemite beta 10.10.1. ( The reason? I read that it would be "preferable" to set this up because of the security flaw-which still has not been addressed,but is another issue ). When I login, I have to firstly login with my admin account & password. Then another screen comes up with both the admin account and the standard account, and a black rectangular shape at the left-hand side of the bottom the page which tells me to login. A white rectangle outline is on both the standard account image and pw section,I then, login my apple ID password into that white outlined rectangle. This is how I get into my computer. ( I had many many other problems from Yosemite which I have remedied slowly) BUT the problem is: I have locked myself out of the admin account somehow. The admin pw I login with, does not work anywhere else.For instance,it does not unlock anything that requires to unlock the padlock- such as System Preferences. I cannot access Disk Utility, cannot unlock or put in admin pw. I cannot turn FileVault off or the Firewall. I cannot upgrade software that requires admin pw. What can I do to regain admin access? (I cannot do this in System Preferences I am locked out!!!)Do I have to reset my default keychain ? What do I need to do ?