Unfortunately, when our BG gets high (usually above 14), we become insulin resistant and need more insulin than usual to bring it back down.
As you say you are sensitive to insulin, take care when doing this and test more than usual.
There are many things which affect our BG - food, exercise, stress and illness are the usual ones. And, as we see our BG rise, stress tends to increase which increases our BG and we end up in a bit of a cycle. So, try to relax and your BG should come down.
Your body may be fighting off some bugs which are causing the high over the last few days. You may not have symptoms which means your bug-defences are doing well.
Alternatively, there maybe something wrong with your insulin. Have you tried changing it and your pens to check?