When I was on Metfartin, I took mine mid meal .
Some people just don’t get on with Metformin, if you need medication their are plenty of others available
It sounds as though you are having a really rough time with it atm so I suggest you talk about changing to something else ASAP
I too suggest getting a glucose meter to check how the various carbohydrates affect affect you as we are all different in this. Sadly unless you are in medications that can cause hypo’s (low blood glucose) it’s very unlikely you will be prescribed one. To me not being able to test, is like driving in the dark and only switching on your lights for a minute or two occasionally ( the Hb1ac)
It’s the ongoing cost of the test strips you have to watch out for ,glucose meters sold in chemists use test strips that cost £15 or more for 50. so many on here use use the SD Codefree glucose meter as it’s testing strips. cost £8 for 50 and initially you get through them atan alarming rate , so cost is important, you will also need to buy more SD Codefree testing strips and a box of lancets .
https://www.amazon.co.uk/Codefree-Glucose-Monitor-Monitoring-Testing/dp/B0068JAJFS/ref=as_li_ss_tl?s=drugstore&ie=UTF8&qid=1506485682&sr=1-1&keywords=sd+codefree+meter+mmol/l&linkCode=sl1&tag=xfm-21&linkId=f39210144fdc26c27738e45b6d957003&th=1
Some people are lucky in that they can control their diabetes without medication by going low carbohydrates the rest of t2s need medications as well as reducing their carbohydrate intake, particularly the starchy carbs , potatoes, rice, pasta and bread as well as those with obvious sugars ie fruit , some fruits are packed with fructose (fruit sugar) anything with berry in its name is often tolerated better, things made with flour and breakfast cereals.
We are fine with protein in all it’s forms and this might surprise you good fats.
I hope this helps.