New to diabetes

I have been on several courses of steroids which have increased my blood sugar levels. I managed by drastically cutting back on beige foods, no bread/pasta/rice/potatoes etc. Although I swapped white pasta for lentil pasta. I also went for at least a 10-15 minute brisk walk after meals, that would usually reduce my BG down into the normal range. I checked my BG pre and post walk, to see if it was effective.