My Lab/GSD is very dependent and has cost me a lot of money. Should I try medication?

I read your pages about dealing with an aggressive dog and what to ask you about my situation.

I have a three year old Lab/German Shepherd mix dog. She is a very loving dog to my roommate and me. She does a have very bad dependency problem which has cost me a lot of money. Most of the time when I leave her, she tries to break out of the house. She will chew on the fence, chew on the front door or anything else that could possible get her out. I have tried giving her a lot of exercise and have found it to be only a temporary fix. I can not leave her in my car or else she will chew on the seat belts of the car. I have had to replace virtually all of my seat belt once. I could live with this if it was the only problem. She also is nervous around new people. She has tried to nip at a few people lately. It seems like when ever a child or young adult gets to close (grabs her or wants to be close), she doesn't respond very well. This concerns me because I do want a child some day and I am afraid of what could happen.

I have tried to see how she is around young children. She is all right at first but she does get more and more nervous as time goes on. Lets put it this way... I'm glad I had her on a leash! I saw that she was starting to show her teeth so I took her out of the situation by taking her away from the people. It was weird. At first she was very happy and licking their faces and then it turned to aggression.

From reading a lot about this, it seems like most people try medication. Is this a real solution or does it just decrease the chances? I love this dog but don't want to forever live in fear of "what might happen."

Regards,
Ryan