Neurontin is usually given when it is thought that some form of peripheral nerve damage or entrappment is present. Based on the distribution of the pain you describe, it sounds like the gento-femoral nerve has been entrapped or damaged. If that is the case, you will find the neurontin very helpful with your pain.
However, the med. must be increased gradually because of the somnolence. Usually they will start you out at a low dose and gradually increase it as tolerated until you get some level of pain relief and can tolerate the side effects. It also causes dry mouth, constipation, and dizziness. Other side effects can occur, but these are the most common ones. We must keep in mind that any drug can cause any side effect, so let your MD know what you experience. Also, I would like to note that some MDs recommend not stopping Neurontin abruptly, but should be weaned.
good luck with it and let us know how you do on it.
Tina