Adding calories to your diet doesn't have to be done all at one time

Adding calories to your diet doesn't have to be done all at one time. I would add some beans to each meal (they have alot of fiber so that could counter act the carbs). I would also make sure that you are eating the right foods. Fruit is a great way to boost the calories while keeping it low fat and it tastes great. Just make sure you test when adding new things so you know what can cause you a problem. We eat alot of berries and some cantelope for deserts. We have balanced meals. Now as far as the number of carbs go. Are you eating 3 meals and 3 snacks a day? If so maybe add things to the snack portions (like fruit) to up your carbs per day or just to the meals but not all 6.
We all have to be careful with they type of fat we eat. They are not all created equal. Good fats are Monounstaturated fats (i.e. olive oil, canola oil, avacado's). The bad fats that hurt our bodies are the transfat and saturated fat. Transfat's do the most damage as they make the blood platelets sticky. Saturated fats are damaging but not so bad as trans. Stay away from both. Saturated fats are those like the fat in a steak, bacon, butter. Anything that is solid at room temperature you want to stay away from.
I would recommend to you that you get yourself a really good nutrition book and read about all of this. That is the one way to make sure that you get what you need. This is a very individual condition and therefore it takes a very individual solution.
Take care and don't worry it will work out.