Can anyone verify my NN diagram if it is properly drawn?
I do not think there is a special kind of format that needs to be followed as long as the image is clear and readable, which (imho) it is for your case. Regarding the last 2/3 layers, the final layer is the output with 1 unit, so you pictured it correctly, along as the article mentions the output shape (that is not a multi-output situation).
Good luck with publication!