While you are working with your lawyer. Do not let your agent go. Talk to the agent and broker. The agent has to clean the mess since he/she made the trouble due to his/her negelence, otherwise you also can sue the agent and company.
You do not need communicate the seller directly. Write to agent about your decision. It is agent's job to inform the seller. If the agent does not take action, it is her/his fault. From now on, write to the agent instead of calling or talking.