Problem in Kameez neck

I am a beginner in stitching, Through net i am trying stitching. First chuidi top also had problem in neck. My neck becomes loose after stitching completely. I cut at the edges still its like that. Can anyone help with this, What is the mistake i am doing.

Also the neck shape changes, the below neck was supposed to be round neck.

i have attached the dress, so you people can tell me the mistake.

Thank in advance

Problem in Kameez neck