Welcome to the forum, you have taken an important step toward improving your health,
Your doctor is right, as your blood sugar level drops it takes a few days for your mind and body to adjust to each new level so this is not something that can be done within a few weeks. A super strict Keto diet would drop your levels dramatically and yes you would feel terrible and most likely promptly give up.
This can be done on your own but will be really difficult and require a tremendous amount of dedication on your part to keep evaluating and adjusting the baby steps required to slowly but consistently improve your conditions. If you want to go at it on your own, there are plenty of us here that can give you help and suggestions.
You seem to be the ideal candidate for Virta Health. I have no financial interest in their company but their methodology appears well in line with what you need so you may want to check them out. There are others as well, but Virta is getting great success with patients that have your particular issues. You can check out their website at:
Keep us posted on how you make out and how we can help. There is always someone on this board that has faced your similar issues and is ready, willing and able to pitch in. We will all be rooting for you.