Asante,
Welcome and you've come to the right place.
You don't say how long you've been diagnosed, as long as you've been on Metformin? How has your GP been? Have they just prescribed you Metformin and given you a few leaflets to look at? Have they spoken to you about diet?
There's a lot of information to take in at the beginning, but, as I've said, you've come to the right place - there's a lot of experience within this forum.
Side effects of Metformin include stomach discomfort (to put it mildly), but these should subside after a while. I've found taking them during a meal helped with those feelings. There is a slow release (SR) version of Metformin which should have milder side effects, ask your GP to be put on those if the side-effects don't subside. As you can see the Metformin is helping you with your BG levels.
You are obviously testing, how many tests are you doing in a day? Are you being prescribed test strips? The important thing is interpreting the results and acting upon your interpretation. You are no doubt aware that what you eat affects your BG levels and there are a number of dietary options available to you, another thing to realise is that there is no single "one size fits all" diabetic diet. Each of us is individual and what may work for one may not necessarily work for all.
Regards, Tubs.