Steroids blew my sugars out of the water a few weeks ago, I was taking them for exactly the same as you, same dose too. My sugars were imposisble to control, no matter what I injected I seemed to get nowhere and hypos were a distant memory. I felt even rougher than I did before and couldn't see properly because my sugars were so high. I kept testing for ketones but had nothing more than a trace. Luckily they settled within 24hrs of stopping so be prepared for that as you'll need to be careful on that day. I'm never going to take them again.