why is this model so hard to train?

[msn199959]

I am a prospective graduate student, and I want to coding this paper during my vacation. At present, the training part of the code has been written roughly, but in the training process, can not know the parameter initialization and some parameter settings of the optimizer? And the model is so hard to train!(Maybe there are some mistakes in my code?) How to solve it? Welcome to contact e-mail msn199959@163.com.