That is why the backup of the data should be done before you try anything else.

Very first thing:  remove the hard drive or SSD, and mount it in an external enclosure.  Attach it to a working system and back up the files you cannot afford to lose.

Then proceed with the troubleshooting.  

Do nothing else to the system until you have a backup made and verified.

'

Thank You, the thought of losing all of my research is making me nauseated.

Perform a hard reset.
Turn off the computer.
Disconnect the AC adapter or power cable from the computer, and remove the battery (for Dell laptops with removable battery).
NOTE: For Dell laptops that have a nonremovable battery, see the Dell knowledge base article How to reset Real Time Clock (RTC).
For Dell laptops with removable batteries, see the User Guide for your Dell laptop for step-by-step instructions to safely remove the battery.
NOTE: On select Dell Latitude laptops, try to recover the laptop using the forced ePSA method from a POST or boot failure. To learn more, see the Dell knowledge base article How to Use Forced ePSA to Recover from POST or Boot Failure.
Disconnect all devices such as USB drives, printers, webcams, and media cards (SD/xD).
Press and hold the power button for 15 to 20 seconds to drain residual power.
Connect the AC adapter or power cable and the battery (for Dell laptops).
If your Dell computer can turn on but is unable to boot into Windows, identify the symptoms and follow the appropriate troubleshooting guide.
If your Dell computer is not able to turn on, follow the troubleshooting guide for no power symptom

If your Dell computer is unable to boot into Windows, perform a hard reset. For Dell laptops with removable batteries, see the User Guide for your Dell laptop for step-by-step instructions to safely remove the battery. Try to recover the laptop using the forced EPSA method from a POST or boot failure.