Help needed

Hi, I was diagnosed with type 2 3 years ago. After being on medication for 2 1/2 years my blood sugars were not coming down or under control. GP put me on Isophane Insulin 10 units per day. I was told that time I took the insulin did not matter, so have been taking it at approx 2pm every day. Have cut down carbs considerably. My sugar levels range from 2- 12 sometimes higher, and I cannot seem to find a link to what I eat. Generally at teatime it is high, bedtime its generally low and when I wake in the morning it would be slightly higher than when I g to bed. I'm at a loss how to control this, can anyone offer any advice please? Thank you