Transfer learning - small database
Seeing your graphs it does not show that the model is not learning, as the training accuracy is high. If the model wasn't learning anything even this would have been low. Also, you are right that the model is overfitting because it is performing very well on the training set and poorly on the test set.

The overfitting scenario is also confirmed by the fact that you have a very small dataset. You might want to fine-tune all the layers of the resnet as shown here. Also, try early stopping and dropout to prevent the model from overfitting.