Lows, highs, and especially rapidly changing blood glucose levels can really tire one out. How low were your readings this morning?
Whenever I make changes, like adopting a new exercise program, I like to watch my blood sugar readings more closely. I use a CGM and test frequently already, so what I do is to upload my devices and look at various reports to try and untangle things.
I see in your profile that you use a pump, diet and exercise to control your blood sugar levels. I would recommend that you start to keep a journal for a short period, maybe a week. You can then learn some things that will help you to adjust insulin, exercise, and food to prevent large and frequent blood sugar swings.
I'm retired now but during my work life I remember taking sick days to allow me to recover from low blood sugar events that rebound to multi-hour high levels. It is tiring.
If it were me, I would track basal rates, boluses, your food descriptions including serving size, exercise intensity and duration, and anything else that you feel impacts your blood sugar levels. I know this is a lot of work but you will learn some valuable lessons.
Have you read any blood sugar management books like Think Like a Pancreas by Scheiener or Pumping Insulin by Walsh? They provide a good deal of tactics to help straighten out the situation you are in. Invest in your knowledge about diabetes. It's one of the best things you can do for yourself long-term.
I don't know much about the thyroid but I also have hypothyroidism. I don't think it has affected my blood sugar situation that much but I'm aware of others here that struggle with getting their thyroid under control.
Good luck to you!