How to prevent low at night ?

I suspect that like many type twos you are less resistant to insulin later in the day.
I would point out though that your morning level is not over 7, but ALWAYS under - you might reconsider your dose in the light of that simple fact, as dropping so low is dangerous.
If you are afraid to make changes even when you are going so hypo, please speak to the person giving you instructions and let them know so they can hopefully give you explicit instructions on management.