Argh! Cehua, I'm so sorry. I've been completely misunderstanding you. When you say protein, I think protein source e.g eggs, meat, fish, etc.
It's been a while since I've been strict with my diet, so I just didn't get you for a while there.
The solution to what I now think you're asking:
1) protein shakes - this is what I've been using for the last 3 or 4 years, and at any given time, you will find a tub and a half at my place. It's the
best value - 5lb tub and each serving is 23/2/1. It tastes decent. I always make a shake out of it by adding blueberries or half a banana - this ups the carb content but if you drink that right after a solid workout with weights, the carbs go right towards recovery and technically don't count as part of your daily cals. There's some science behind that, and I can dig it up for you sometime in the next week or so if you like...
My brand: Optimum Nutrition - Whey Protein
2) Egg whites - you lose some of the protein from the yolk but at least you don't get the fat. Some people will have an omelette of 5 egg whites (maybe a yolk) once or twice a day, which does add up.
3) Tuna - has the highest protein content of any protein source with very little fat.
4) Cottage cheese - has the highest (I think) protein content of any cheese with very little fat if you go with the low fat kind
5) Other low fat fish
The prime source for most people, especially bodybuilders is chicken breast
- very low in fat. I buy frozen bags of these. But, I know you don't eat chicken.
Beyond the foods and whey protein listed above, I'm afraid I'm tapped out. Hopefully, your doctor will have more ideas for you.
eta: also check into various beans, but you have to count the carbs in those as part of your carbs.
I may not check back in for the rest of this weekend since I need to get myself organized... but I think I explained everything I know very well.