Don't feel bad. I was never able to tolerate protein drinks after I had my surgery. They made me hurl and it has taken over 3 years for my stomach to accept them. I didn't complain, I simply chose other methods. Nonetheless I still lost over 200+ pounds and never gained one inch in my post WLS journey.
You've been told to eat in moderation, but the real secret to that methodology is using great ingredients. Food is meant to be enjoyed. Play with the formula until you find something that works for you. Good luck!