To visualize the losses for the training, start the TensorBoard server as follows:

tensorboard --logdir=logs

Now, open localhost:6006 in your browser. The SCALARS section of TensorBoard contains plots for both losses as shown here:

The loss plot for the discriminator network for Stage-I is shown as follows:

The loss plot for the generator network for Stage-I is shown as follows:

Loss plots for the generator network and the discriminator network for Stage-II can be similarly obtained from Tensorboard.

These plots will help you to decide whether to continue or to stop the training. If the losses are not decreasing anymore, you can stop the training, as there is no chance of improvement. If the losses keep increasing, you must stop the training. Play with the hyperparameters and select a set of hyperparameters which you think can provide better results. If the losses are decreasing gradually, keep training the model.