I had that problem in the past until I started eating something with a lot of protein content before bedtime, or during the night after sleeping a few hours. Your 2 AM check would be a good time for that. Depending on your level at that time, you could =ave some fast acting carbs combined with protein, or just some protein alone. The protein lasts a long time and should hold you until you get up in the morning. I used to use peanut butter and crackers. I experimented to determine how much of that I needed, and then I ate that almost every night to avoid morning lows.
Now I use a pump and a CGM, and my control is much better. I rarely need a snack during the night.
There are Dexcom support groups on Facebook that might help you with getting Dexcom supplies.