El Capitan causing continous loop at restart...will NOT boot in safe mode, only recovery.

Hi guys, I have been raiding these discussions looking for a solution for my issue. I have found similar problems but none the same. So here goes....

I have a 2008 20 in Imac, I have not updated in years so when El Capitan came out and I could go straight to it without getting the few systems in between, i was excited. So I was previously running 10.6.8 Snow Leopard (yes i know, i slacked terribly). Ok, now for the issue, I downloaded El Capitan 10.11 from the app store with no issues, it worked fine for 3 or 4 days until I shut down my computer. Upon starting it back up later in the day it cuts on to its normal screen and does the normal chime noise and the apple appears and then boom it goes directly back off and starts that over. It does this over and over and over and over again and probably would never stop if I didn't hit the power button to cut it off. Also there is no code on the screen at all, i have seen similar issues and people had code appear on their screen with the apple logo. It will NOT restart in safe mode the only mode i can get it to start in is holding down the command button and the 2 options that come up are "mac and recovery". I went into Recovery mode, i have called apple and i did everything they told me (they have no clue whats wrong with it). We went into disk utility and did the repair on the hard drive with no luck, it said all was good, no error messages nothing. Let it be known that I do not have a time machine back up.....So that option is out the window. So next thing i did was my only option left which was to reinstall el capitan. so I did and it worked like a charm, with the same issue.....if my computer was ever shut down i was put back into the continuous reboot loop once it was cut back on. So I have installed el capitan one more time just so i can back up everything i need to an external hard drive. Apple has told me the only thing left to do is wipe the computer clean and re install. So that is next, unless there is someone out there that can help me. Either that or I never cut my computer off ever again and pray the power never goes out :/ sigh.