I am a physical therapist assistant, and there are no short cuts to your body healing. Suzieq2010 is absolutely right. Nerves get cut during surgery and what you are experiencing is totally normal, however, your shoulder hurting means two things. 1) you are compensating for lack of motion in your hand by overusing your shoulder and moving in ways you do not normally, and 2) your nerve pain perhaps coming from your neck. Has your PT evaluated your neck? Your nerve roots begin there and run down the arm, sometimes some neck exercises can help if that is where it originates.
It takes time. Nerves regenerate at 1mm a month. There is no speeding that up.
If you are experiencing hypersensitivity, you need a desensitization program. Basically, it may seem counter-intuitive, but you need to touch that area as much as possible. Stick your hand in rice, beans, rub with cotton balls, anything you can do to bring stimulus to the area will help with sensitivity. This is only for sensitivity, not tingling/numbness. I am sure your PT would have recommended this if she thought this would help.
The nerves often come back from surgery but it takes time and patience. I am sure it is so frustrating for you, but hang in there and trust your PT