Hi. I Have Type 2 Diabetes And Have Had It

Hi. I have type 2 diabetes and have had it for years ... Controlled with diet and metphormine at night as fasting typically high. I stopped the meds, I have gained 30 lbs and am always tired and lightheaded. I'm also a chocolate fanatic. Because I haven't felt good I checked my sugar levels today. At 12noon after only having 2 cups of coffee it was 158 I just checked before dinner and it was 371. How high can it go before it's too dNgerous?