Solved by vdw in post #4 
              
              
                Two comments: 

You define self.out=nn.Linear(2048,1) but your x after flattening is (16, 128). So it should be self.out=nn.Linear(128,1) to fit your current setup.
For a text CNN, Conv1d should be the way to go. Sure each data item is 2d with (seq_len, hidden_dim) but 2d convolutions don’t make sen…