This is exhausting

Has anyone found any tricks to overcome their negative self talk? I've been told I'm handsome but I can't bring myself to look in the mirror. I crave external validation and it's so unhealthy and unsustainable to rely on it exclusively. Between this, my bipolar disorder and ADHD I feel like my brain is being tossed around like a ragdoll.

I've pinpointed three insecurities: height (5'8"), a self-perceived wide face, and love handles (though I have an average build). My height is the worst to overcome because male height comes up so frequently in casual conversation. I'm a nurse and work with female nurses, and more than a few mention how shorter men have no business even looking at them. I wish I could tell them to stop but if I do I'm seen as insecure and therefore even more unattractive.

It's so mentally taxing when I'm in-between relationships. I lie in bed racking my brain wondering if problems in past relationships could have been overlooked if not for my height or appearance. I lie and tell others I've grown out of my insecurities but I'm suffering silently. The worst part about this is not knowing what exactly factors in to being rejected, and as a defense mechanism I sometimes avoid women altogether in a romantic sense. What can I do to fix this?