Leaving Property Before Lock In Period

We have rented a house in July 2020. My mother's health is getting worst here, she has vertigo, spondylitis, and hypertension. The atmosphere here is making her more stressed. She is in a depression. We would like to vacate this flat before the lock-in period. Our broker told us after an agreement that we can vacate the flat before the lock-in period if have any issue. Could you please help me, how can I go ahead. I am thinking off putting a request letter to the owner. Kindly suggest