I agree with those who recommend you find another PCP. I would be concerned about this doctor's fixation on your BMI. First of all, as a bariatric patient, you might not need to have a BMI within the "normal" range. I saw a video on YouTube a while back (someone linked to it on this forum) by a bariatric surgeon talking about the best weight for bariatric patients and he suggested that a "normal" BMI may actually be too low. So the first problem with this doctor is that his advice for you to lose weight might not even be correct.
The other thing that bothers me here is that I have a dear friend who went to her PCP complaining of malaise, and the doctor dismissed her symptoms and told her she would probably feel better if she dropped 10 pounds (and this is someone I have always envied because she has always been in great shape;). Turns out she had cancer. I would be wary about a doctor who jumps straight to losing weight as the cure for everything.
Something I appreciate about my PCP is that she never commented on my weight. She suggested I change my diet and be more active to lower my blood pressure and blood glucose, which are obviously associated with weight loss, but she recommended actual actions and not just, "lose weight." Likewise, she didn't praise me for losing weight, only for improving my health. I wish more doctors would take that approach instead of just using BMI as an all-purpose measure of health.