Of course lying isn’t acceptable.

But telling them you became so overwhelmed with the tasks that you couldn’t do them and had to take medical leave to cope isn’t going to land you a job. You can’t tell them that making 30 slides power point presentation is beyond your capabilities and made you sick. No way no how anyone would offer you a job in the field. Now if you tell them you didn’t know how to do XYZ but now you took these classes or are enrolled in class now and show them documentation, they might appreciate it.

If you are applying for essentially same job position that got you so sick you had to go on leave, how do they know you wouldn’t get overwhelmed again? And they’d be afraid to hire someone who could be pushed to illness with tasks they assign. They’d not offer you a job. They don’t want the liability. Essentially you are telling them that job made you sick yet you apply for the same type of job again.

I know you stated that you weren’t getting responses for other positions but something has to give. Do you work with recruiters? Vocational services? There have to be other jobs out there