Pity is absolutely right....

I would start by evaluating what you eat now. Figure out things you can eat that will benifit you in your goal to gain size. It doesn't matter if you like them or not. If you hate them, eat them first and leave what you like to eat for later in the meal. I would find a protien shake that you enjoy drinking. Actually, you really don't have to enjoy it, just get it down. Anyone who has been around for any length of time remembers the crappy shakes that were around in the 70's and 80's. Some of them were absolutely horrible. And they don't have to be expensive either. There are many sites where you can buy protien in bulk for much cheaper than the name brands. There are actually threads here that you can search to find the names of those suppliers. But keep in mind that it doesn't have to cost you hundreds of dollars each month to put on size. Many of the things you might not like eating could be the key to your gaining weight.

As for your doctor. You should remember that most doctors know very little when it comes to bodybuilding or even nutrition in general. And as I've stated before, many still have food charts on their wall from the 1970's. Your best sources are going to be the internet. This site, Anabolic Review and many others will help. Another thing I would mention is, if there is a gym in your area and you can afford it, join up. Most have small monthly fees. Look around first and find one that you like. Ask people questions. It's amazing how helpful some of the biggest guys in the gym can be. Most of them don't mind helping someone out when asked. And those that don't aren't worth knowing anyway. Check back here often. Do searches on what questions you have first and by all means, when you can't find it, ask. As I've also stated before, there are several guys here that really know their stuff, you'll figure out who they are fairly quick. All of them are nice guys when asked for advice in the right way.. Good luck and if you have anymore questions just ask.