Professionalism During Notice Period
Checking your mobile phone like this is highly unprofessional. You should keep a password or something to secure your phone so that no one can access it. Resigning from the company due to any reason is your individual choice. Now, there is only one week left in which you are required to finish your pending work, which you should have completed during the entire notice period.
Many employees tend to neglect giving a proper handover when leaving the company, with a mentality that says, "If I am leaving, why should I bother?" This attitude is unprofessional because, many times, the company faces problems understanding the tasks done and pending work if the handover is not comprehensive.
However, as you mentioned, if they are harassing you because you are leaving the company, try to be honest with yourself. Finish the handover properly and, at the same time, provide a medical reason that your health is not well. This may prevent them from troubling you during your notice period. If possible, request an extension to finish the given tasks and maintain a record of all handovers. This record can be useful in the future to demonstrate that you provided a proper handover and may aid in obtaining certificates.
While you are still with the company, try to maintain a positive relationship. Forget about the past incidents and leave on a good note. The fact that they are trying to retain you indicates that you are a valuable employee to the company. Therefore, aim to depart on good terms.
Good luck to you!