My landlord refused cash payment for rent?

i moved into my home the last week of October. I offered to pay to my landlord for the days I was there plus the utilities since they would not switch over until the first of November. With the cost of the move and all the deposits I sent the money owed for October, utilities and the late fee since the remaining rent would not be paid until the 21st. My landlord sent me a letter stating that I had till 6pm on the 21st. No problem. I was running late on the 21st and tried calling him from 3pm until after 9pm to let him know I was stuck in Dallas due to car problems and would be there just as soon as I got in. I went to his home the gate was locked and I did not go up since it was dark. I went home called him at 730 am to tell him i was on my way. I got to his home he was not there. I went home to check my address to make sure I had the right place which i did but he had in the meantime put a letter stating i had three days to move out I was in violation of my rent. I went to his home with the cash. He said put it in the mail. I said Iwant to pay the rest of my rent he said put it in the mail. He did not accept cash. i then went and bought a money order and called him and told him i mailed it he said the letter stands he wants me out in three days. can he do that? my real estate agent says he also violated the lease. Help I dont know what to do.