I think this is the problem - shifting blame. It seems to be someone else's fault. Either the doctor, or other models taking the work. As soon as you take the fight to them and not sit back and feel sorry for yourself, the comments and possibly even work may follow

I feel like this conversation was derailed.    Here's what I see in the original question:
    "What am I missing to get more comments, and photographers interested in shooting me."
    "I'm on here to be myself and creative."
    "Give me so feedback on my pictures."

To me this implies you are not here to make money.   So why are you here exactly?  To get some great shots of yourself (and comments)?  To have fun?

The comments and interest come two ways,
1- Nudity will tend to get you comments and interest.   I will let you decide if it's the type you want or not.  No skill required really
2- Smoking hot, no real talent required from photographer or model.
3-  And finally an ability to really bring it with expression, so that you connect with the viewer.  Some of the best images I've seen here are people with a non typical model body, but a really amazing expression.  Although this is usually supported by good photography.

At the moment, your images are kind of the first.

18+
http://www.modelmayhem.com/portfolio/pic/18576542

For example, the pose here is uninteresting, the slack jaw expression here is terrible.



This one is much stronger.  Notice that you got a better response with your clothes on, because the pose, expression, and composition are much stronger.



This image, while not as popular because you've got more clothing on, is actually your best one IMO.  You connect with the audience, you have a real and pleasing expression on your face, and the photography is reasonable.

My advice depends on what kind of interest you want.  If you find some reasonable photographers, and get some reasonable shots.  It will generate more interest.    You could also get images that more explicit, go more fetish, and erotic and generate interest that way, but you may not end up with images that are stronger.

Hmm.  I've been in the medical field for 17 years and this would be the first time I've ever heard of a doctor suggesting a patient be overweight.  I'd suggest getting a second opinion.

Also, you're in St Petersburg, Fl.  Take a moment and browse the models in your area so you can see what you're up against.

Hammer, meet nail.

As rough as what DVP stated may sound, he's right. Not having transportation means the photographer has to spend time and gas to pick you up that he wouldn't have to with someone else. If you trust what your doctor says (and aren't simply shifting blame to him) and are at a weight you're happy with, then good. That's awesome. It's a cliche statement, but beauty really isn't a number. That said, there's a big difference between general beauty and what the modeling industry is looking for. It's a simple fact that you would receive more interest here if you lost weight, but since you're here to express yourself and not make money it's your own decision.

Also, find a way to get more pictures of this style and quality. It's working for you. This is definitely your best picture:


This one is well done as well:


I like the idea behind this picture, but I think it could be better executed. Maybe you could try for something better along the same lines to replace it. It has potential, at least.

She is not overweight. 144 lbs at 5'7 is a BMI of 22.6. 18.5-24.9 is considered healthy. Overweight would be 25 or higher, and obese would be 30 or higher. Sure she is larger than models in certain genre's, but she is not medically overweight. Saying that she is overweight is demeaning and uncalled for.