Diabetic Mess

Hello, I am trying to log all my food and fitness activity to try and control my type 2 diabetes. Just wondering if anyone on this list has diabetes and are willing to share some success secrets to help someone (me) who is struggling getting their blood sugar under control.

I can eat healthy all day, and the next morning my fasting blood sugar measures in the 160-180s. But if I have a hot fudge sundae the night before, my fasting blood sugar level the next morning can be as low as 125. I just don't get it.

Thanks in advance for any help.
Wannamarting45