It is fairly common to see the loss decreasing for several epochs and then start increasing. In this situation there are two common strategies.

Stop training when the validation loss stops decreasing - this is often called “early stopping”
Decrease the learning rate when the validation loss stops decreasing - this often, but not always, results in the loss going down further.

Generally we consider that the validation loss has stopped decreasing, if it hasn’t hit a new low in 10 epochs for example. For your model and data, 10 epochs might be too many. Feel free to adjust as necessary.