Intermittent fasting (a minimum of 12 hours overnight) is supposed to help preserve pancreatic beta cells and there is some initial research showing periodic fasting (longer occasional fasts) may actually regenerate them, so likely there are things you can do if you can make it fit your lifestyle. If you introduce any kind of fasting, in my opinion, you need to eat more nutrient dense foods at the times you do eat.
You may need to eat lower carb to lower those glucose spikes and restore some insulin sensitivity.
It wouldn't hurt to visit the doctor to get a Hba1c, insulin etc tests (or whatever they check) just so you have a baseline. Don't feel any shame over being prediabetic. There are all kinds of ways people end up there and a doctor should be very supportive of a patient who's done some homework and is willing to work to resolve issues.
Feeling tired after you eat is not good...especially as you have the demands of small children !!! You'll feel SO much better once you take control of this.