I need help with my BFNN model to get good R2, MSE, RSME, MAE and MAPE.

I need help to optimise my backpropagation feed-forward network for data prediction. I have already done the coding for the neural network fitting but my R2, MSE, MAPE, MAE, and RSME values are not good. I also need to plot a boxplot, graph of accuracy vs SMAPE and predicted vs actual output.

The attached excel file is my dataset: the first 4 columns are the inputs and the last column is the output. And attached MATLAB file is my BFNN simulation.