Does reframing help? It might not but if you start with the co-worker thing. Does it help to remind yourself that your reaction to the co-worker is possibly over the top - 1. the co-worker probably is more focussed on herself than you, 2. you know you are reasonably competent and have value to the company, 3. Even if the co-worker was thinking that about you - so what? But I doubt the co-worker has given you as much thought as you are spending on her.