I had my first bad meal since diagnosis last week and had fasting blood sugar in the 8s for the next couple of days. I was really annoyed with myself and thought I had ruined things but it did settle down and I was seeing 6s again. I'm on one metformin too, I'm supposed to be increasing it weekly but things havent been so bad so I'm sticking to one at the moment. I was going to increase my dose but luckily it came back down. Hope your readings settle soon.