Hi Lews,
Your Glip dose seems low. also, you were diagnosed not too long ago,
I don't think that you're becoming resistant to the meds. look elsewere, even probably increasing your meds. or at extended release meds.
how's diet, exercise, your weight,drinking water. carbs, ?
One of the drawbacks of Glipizide, I've read, is that damages the beta cells over a long period of time, & the beta cells are the ones that produce your own insulin, it's something to think about, do more research & talk to your health team.