Hi,
Steroids are known to raise blood glucose - sometimes by a great deal.
Make sure you track your blood glucose and ketones carefully, and keep a record of them to show your doc.
I should get back in touch with whoever prescribed the steroids, and contact your doc (or whoever treats your diabetes) and discuss the raised blood glucose levels with them. You all need to weigh the priorities of your other health condition, your diabetes, and the risks from increased blood glucose, and see which is the most urgent. A lot will depend on whether you are going to be on the steroids long or short term, and the doseage.
Best wishes - it must be a stressful time.