Hi: 
We All know what you are going through, as we have All struggled through at least some, if not all of the Stages of the Grieving Process due to our loss of a “normal working body” or “dreamy thoughts of what a normal working body should be”.
Sometimes even many years later, we may go back into Denial and fall off the “Diet, Exercise or even Medication Wagon” for a short while. Or go into a day or week of Depression because we have this or that disease, etc. Grief is not just for the Loss of a Loved Family Member(including Pets) or a Good Friend. http://www.recover-from-grief.com/other-grievous-loss.html
Some People never get through the G. Process to Acceptance and Rebuilding. I Truly hope that you will get through this.
Go through the G. Process at your Own pace. Don’t be shoved through it by Family, Friends or Acquaintances. Try not to feel Ashamed or feel like you are Less of a Person because you have Diabetes, etc. It Is Not Your Fault!!
Yes, Diabetes is overwhelming. You have learned the basics, so refresh those. Go slowly in learning the rest. Since you are going through the Grieving Process, most of what you learn now will just be a jumbled mess in your brain. Learn 1 or 2 helpful Diabetes Tips a week, if you want or not.
Keep a “Diabetes - Helpful Tips” on a Word page or whatever you have. Type in and Save Tips that you come across, for later viewing when you are Ready to absorb them.
If you haven’t already, there are many helpful Groups(click on Groups) at the top of the page to Read info and to maybe Join some Groups, if you like.
All these Lovely Ladies have definitely given you some Good pointers.
Btw, Most Diabetics, Do Not always have Perfect numbers in the Perfect Range. There will always be Something to throw us off even if we run a Perfect ship. Things like Stress(high or low numbers), Hot or cold Weather(high or Low), etc., etc., and that Is okay, as long as it is not too often or prolonged.
You are young, so you have Some Time on your side! You Will Succeed and Live a Long Useful Life!! Great Luck to You!!! 