अमर्षस्य by indignation, अन्तम् put an end, गतःअस्मि I lost, धर्षणा insult, सम्प्रमार्जिता gained reward, मया by me, अवमानश्च indignity, शत्रुश्च enemy, युगपत् all at once, निहतौ by killing

"I have put an end to the indignity that I lost. I gained reward for the insult. The indignity offered by the enemy has been wiped out all at once."