Needing a LOT of sugar to treat hypo

Hi all, wondering why this is happening to me, and if anyone else has experienced this too.

When I started taking insulin, it was pretty easy to treat a hypo. Take 15 grams of glucose, wait 15 minutes, test again.

Lately, I've found that 15 grams of glucose is not even close to what I need to take. Even a mild hypo (say 3.9) I need to take at least 80 grams of glucose.

Last night I woke up at 2.5, and after taking 160 grams of glucose, I leveled off at 6.5.

I'm just concerned as to why this is happening. I'm getting way fewer hypos, but I'm concerned at how much glucose I need to not die.

What do?