I got a speeding ticket for 94 in a 70 in Louisiana on the highway.

I received a speeding ticket on a Louisiana highway for going 94 in a 70. I flew back to my home state later that day. The court date is mandatory. And I couldn't afford to fly back for a court appearance. I called the DA for the county and he said the judge requires me to be there in person. I cant pay a lawyer to go for me. The DA also told me that since it's just a speeding ticket, do not worry about it. He told me that they wont send people to arrest me and to just handle it when I come back to Louisiana. The problem is, I received a letter from the clerk of courts stating I have a warrant for my arrest because I did not show up to the court date. What should I do?