Your comment ‘in my head I’m not satisfied’ set off alarm bells for me & I’m worried you may have developed an eating disorder of some sort even though you say you want to put on weight. Have a chat with your surgeon/doctor & ask for a referral/recommendation to a therapist who specialises in disordered eating.
It’s hard to judge your weight without knowing your height but I would worry you are underweight at 100lbs. What does your surgeon or doctor say? I would also think you are eating very low calorie to be at that weight too so if you want to gain weight the first step would be to increase your caloric intake. You can do this easily without introducing cakes, cookies, etc. into your diet. Simply increase the nutritious foods you already consume. This can be through snacks & portion size if your portions are smaller than recommended. Not knowing your diet, consider adding multi/whole grains. Snack on cheese, fruit, vegetable crudities, nuts, some good fats like avocado. Your dietician would be best placed to advise you on this of course.