Hi, I too take Metformin but the XL which isn't supposed to be crushed. I now take 2 regular Metformin and it's awfully bitter. It's so important to take your meds and I bet that's why you feel crummy. Without the metformin your sugar is probably going way up and that's why you're so tired. When it spikes from eating and then eventually goes down it's exhausting not to mention may be causing damage. Soon you'll be off it but in the meantime, crush your pills and take it with apple sauce it covers the bitterness.
I bet you'll be off it in no time.