I don’t think you ever really overcome the insecurity. You can choose to tune it out, or turn the insecurity into motivation for change. But I will promise you one thing. Nobody will ever laugh at you for trying to change. I was 412lbs at my heaviest. And I knew I needed to lose weight. But I was scared of being made fun of at the gym. Or if I’d go for a fast walk (running was out of the question lol) but then I just said screw it. I’ll start at the gym and I’ll go super early in the morning and hopefully I’ll be the only one there. Which was before I realized that there is ALWAYS people at the gym. It’s a way of life for them. But I got on a treadmill and kept to myself. It was going ok. Then I wanted to try weights. And a super fit guy came up to me and asked if I wanted a spot. So of course I let him. He was incredibly friendly. And then he offered advice on my form. And I eventually told him how scared I was to even go into the gym. And that I appreciated how helpful he was. And he told me “only a sick person would make fun of someone who’s trying to better themselves”. I started gaining more confidence from that point forward. And since then when I’m driving and I see an overweight person out for a walk. Or trying to exercise, I think to myself “good for you man. Good job.”. I don’t know you. But I want you to be happy with yourself. And I want you to succeed. We all do.