A sudden increase in fasting like that - assuming no change in diet or medication - can be due to things like stress, infection or lack of sleep, all of which increase your level of insulin resistance. Some medications do the same, e.g. Statins, steroids.
Anything going on in your life? Or did you change your eating habits?
If none of the above apply, it may be that your ability to make insulin is starting to decline. That happens to some people with T2 - beta cell burnout after many years of making as much insulin as possible to counteract insulin resistance and a high carb diet.
What medication are you on? Do you eat low carb?