Hey, thanks for that!
the question is a bit abstract, maybe.
How do I combat insecurities? I try to recognise that it is not something to combat. That gives it too much power. Acknowledge, and understand. Describe for yourself how those feelings arise, as emotional states and physical patterns in your body.
In looking, really looking, at our bodies and our self-images, and simply noticing and describing, as if you were to draw yourself, you can start to disassociate the value judgements from what is really there.
I am this tall. My torso is longer than my legs. My shoulders sit at these angles, one different from the other. My head feels heavy when I hold it like this. When I feel shy, my sternum collapses downwards, and my shoulders roll inwards and down, and keeping my face oriented to the horizon takes more effort. Etc.