Do I have grounds for suing in small claims court? How?

I moved out of my apartment because my roommate was emotionally abusive and intimidating. The lease goes until August and I am interested in finding a new tenant to take my place. The landlord has told me that I cannot sublet the apartment unless my roommate approves of the new person. (They would be moving in with her) I feel that my roommate is purposely not choosing a new tenant. This is evidenced by her not setting up appointments with potential tenants, turning people down for petty reasons, and refusing to meet with potential tenants that I have referred to her. She refuses to answer any questions about who she has shown the apartment to, how many people have responded to the ads she has placed, etc. Whenever I try to communicate with her about subletting, she lashes out at me verbally instead of addressing the issue at hand. Today I told her that she needs to get back to a potential tenant who would like to see the apartment. She responded by telling me to stop talking to her, or she would report me for harassment. I have explained her behavior to the landlord and even forwarded him nasty e-mails she has sent me and he refuses to do anything to help. I have also provided evidence to him that she is purposely not trying to find a roommate (e-mails from potential tenants who state that my roommate never talked to them). I do not have the money to hire an attorney so the only thing I can really afford is small claims court. Do I have grounds to sue her and/or the landlord in small claims? I want to get back the money that I have had to continue to pay in rent, since I am not able to get out of the lease.