I've Been Diagnosed As Type 2 Diabetic For Around 2

I've been diagnosed as type 2 diabetic for around 2 years (taking metformin and insulin injections) and lately I've been suffering with neck pain, occasional tightness of the throat and general aches and pains. These have got worse since I had the flu jab last week so could it be that or are these known diabetic side effects?

Thanks.