So I was about to go to bed. Checked before I laid down and it is 89.. now i'm so nervous I can't sleep...I don't understand why it hasn't stopped dropping yet and now I'm afraid I'm going to have a low over night.
That is indeed different! But remember that one experience does not a pattern make! There can be other factors involved; you don't know that your night time ISF is 1:100 until you've checked it out several times! Anyway, let us know how it goes!
The BG drops in most people over night. Especially around 3am we have the highest sensitivity to insulin. This is due to vivid dreams consuming carbs, muscles reloading their glucagon deposits and the liver reducing the conversion to glucose - hormonally induced.
Thus I would recommend to define a critical threshold for the night. Lets us assume you will drop 30 points from 1am to 3am. Thus you should go to bed with more than 120mg/dl. This means you will have to eat something if you are lower than that. With 89 you could eat 12g of carbs and that would bring you to a good starting position of 89 + (12g * 3mg/dl) = 89 + 36 = 125mg/dl.
It gets more complicated with Lantus. Some users repors massive drops after the night shot of Lantus. In this case the Lantus is not acting equally for 24 hours. Instead some of the action is concentrated on the first hours after the shot. In this case it is recommendable to split the dosage in two shots every 12 hours. The better alternate in this case - in my opinion - would be to switch from Lantus to two shots of Levemir. In both cases the split has the advantage that you can be sure that 24 hours are truely covered with basal insulin. This is not guaranteed with the one shot pattern (not for Lantus and not for Levemir).
Theres no way I could have ate 12g with my blood sugar at 89 or else I would have been sky high lol. By 4 hours after correction I was at 75 I decided to not let it go any lower and ate a little bit of <1 cheese and 1 tbsp of PB. This made my blood sugar go to 120 I woke up 122 so this is ok for today as I usually wake up in 140's to 150's. Plus I didn't want to drop any lower then the 75 but didn't want to treat since it wasn't actually a low but it was also really late and wanted to go to sleep. Anyway though so by 4 hours I went from 200 to 75 with an ISF isn't this kinda extreme? I hope it doesn't drop me like that everytime.
To really grasp your daily problems and challenges I would recommend to keep a diabetes log for some time. If you like you can create an account in my Glucosurfer project. This way you can share your diary in discussions and we can give you some feedback.
Yes, that was a big drop, but that doesn't mean that will happen every time. Just keep testing your ISF, testing and keeping records. Things don't always follow consistent rules, and that's why you have to establish a pattern before drawing any conclusions. Sounds like it worked out ok if a bit nerve-wracking.