Am I responsible for anything after eviction case was dismissed with prejudice?

I signed with an apartment complex with three other girls (college) that turned out to be really shady (I thought it was an application NOT a lease, my mistake) (they don't run background or credit checks and never explained this lease to me or gave me a copy). Anyway I gave the landlord 30+ day notice that I would not be moving in because I didn't feel comfortable with my financial situation. He basically told me I was SOL unless I found somebody to take over my room. (This was made worse by the three girls turning down the potential roommates waiting for a friend to take over my room- which she never did) I never paid a security deposit, turned in a cosigner form, or took keys for possession of the apartment! (I never entered the apartment EVER) I had to go to court and he is trying to charge me for three months’ rent. He never showed up and his lawyer talked to me beforehand and then told the judge to dismiss the case with prejudice. Am I responsible for any costs then? Can he go after me again?