Hi Armina, welcome!
Have you tried timed-release metformin? Regular metformin caused me stomach troubles too, but I have no problem tolerating the timed release.
Generic timed release metformin hasn't been available very long. Before, you had to buy brand name Glucophage.
As far as the slow weight loss, it may just be that SB isn't low enough in carbs for you to lose.
We insulin-resistant Type II's are carbohydrate intolerant, there's no getting around that, as much as we may like to.
Our bodies have lost the ability to turn carbs into fuel for our muscles, so it gets stored as fat.
You need to expirement with how low you need to drop the carbs for weight loss to start. For me, I don't necessarily need to stay at induction levels... I aim for no more than 30 net carbs (carbs minus fiber) spread evenly across my day, and I'm having an acceptable rate of weight loss.
Of course, I'm starting at a much higher weight than you. You're my goal weight! I fully expect things will slow down and get tougher for me too under 200 pounds.
I take 1500 timed release metformin, 40 Actos, and inject 15 units of Lantos daily. In the 6 months I've been LC, I've lost 56 lbs and been able to come off of Glipizide, as well as my cholesterol and blood pressure meds.
This is not my first time LC-ing, but it my first successful time LC-ing. "That's what diabetes did for me" (smile).