Not able to predict the new covid-19 cases using FB prophet.

I am using Fb prophet to predict the upcoming covid cases every day in month of April. I have a dataset of daily covid cases up to March 2022. I have included holiday, and external regressor such as weekends, or daily covid testing but still, I am no way near the actual covid cases.

I have got high MAE and MAPE,

This is the plot of original data points -

This is my Dataset - y is the daily new cases, new_tests are the daily testing and workingday ( 1 for weekday and 0 for weekend)

This is the additional holiday dataset -

I used these parameters after cross - validation -
```
m = Prophet(growth = "linear",
yearly_seasonality = True,
weekly_seasonality = True,
daily_seasonality = False,
holidays = holidays,
seasonality_mode = "multiplicative",
n_changepoints = 10,
seasonality_prior_scale = 5,
holidays_prior_scale = 5,
changepoint_prior_scale = 0.01)
m.add_regressor('workingday')
m.add_regressor('new_tests')
m.fit(training_set)

```

But I got very poor results - The blue line is for predictions and black dots are for original points.

The Mean Absolute Error and Root Mean Squared Error are 68862 and 72610 respectively whereas Mean Absolute percentage error is 2702.99.

How can I Tune my hyperparameters or add any other regressor so that I can get low Error? or close predictions. Thanks.