Make sure you are testing before you eat as well to get the full picture of how much the food is raising your BG levels. The insulin you are taking could be ok for what you are eating at certain meals but if you are already way too high then you need to adjust.
I have good control just now but during the periods when I struggle to keep my BG levels down I will test 8-10 times a day, before and after each meal, first thing in morning, last thing at night and anywhere inbetween where I feel too high. That gives a much clearer picture as to when your BG are rising most and why.