Could you post what your model is?
Also, during the training loop print out what the gradients are! They might be really small (where you’d need to just increase your learning rate) or might be equal to near 0 which would indicate a problem within your model! You can print these out by adding this to your train function.
for name, param in model.named_parameters():
  print(name, param.requires_grad, param.grad)