having to change from insuman comb help

I was on metformin for a good few years and got taken off and put on to humilin M3 insulin and that is a mixing up insulin that you have to do in your insulin pen but you have a lot of other treatments to use for diabetes as I am a type 2 Diabetic and has taken me a while to sort out my injection doses which I do by myself and don't have to use a diabetes nurse or doctor as if I am ill that is the only time and when you do, do your insulin it's up or down by 4 units every 4 days until you have the correct amount going into your body every day and night