Hello and welcome to the forum. Sounds like you have had quite a difficult time, so glad you have found us. Although steroids are a very effective treatment for many conditions, they may cause side affects including diabetes. It sounds like you have had large doses of steroids for treatment which can pose an increased risk. Are you currently managing your diabetes with medication? Insulin, or tablets?
Have you had much support or information from your healthcare team regarding your situation? In some cases, diabetes can stop when steroid therapy is stopped, however, in other cases you may need to continue diabetes management indefinitely. It also may be that you had a predisposition to the condition already and steroids speeded this up, or it could be that with such large doses, it was too much as you say, for your pancreas.
How are you managing with your current chemo treatment alongside diabetes?
Pleased that you have found this forum and hopefully someone else who has had a similar experience will be able to share some insight with you. 🙂