Who pays for a defense lawyer in small claims court? I am the plaintiff.

You probably agreed to this in your lease.  Most leases have a provision in them requiring the losing party to pay the winner's attorneys' fees if there is litigation over the lease (sometimes the lease only provides for the tenant to pay the landlord's fees, but in NY, where I practice primarily, such a clause is deemed to be mutual).  You should read your lease carefully to see what it provides.  Regardless, you should not have to pay if you win.  Also, you would only be liable for "reasonable" attorneys' fees.  In a $3000 small claims case, which probably won't involve a lot of motion practice, discovery, or many court appearances, it is doubtful that any Court would approve a tremendous amount as a "reasonable" attorney fee.