Congrats! I am so glad you're doing well!
Mood changes with prednisone or other steroid treatments are common. In some cases, particularly at high doses, more severe mood swings — and even mild depression and mania — can occur. Fortunately, the effects are reversible and mood returns to normal when the dose is lowered or the prednisone course is completed.
If the mood swings continue, switching drugs may alleviate the symptoms. Be sure to tell your doctor what's happening, and discuss dosage and whether a change or reduction is possible.