I made a mistake 5 years ago. I changed my field from materials science to civil engineering. I did a PhD under a professor whose research expertise was not in my research topic. I had to independently work on my knowledge and skill set to become productive and produce research. But, due to lack of technical guidance, I produced mediocre research. My research is very novel and rigorous for my field of research, but the scope of getting a future position in the field seems bleak.
I want to diversify to other area of research, but I don't possess the experience or knowledge to carry out the projects. I am getting rejections from all postdoc positions as I don't meet their requirements.
I don't know what I should be doing now? My adviser doesn't have any connections in my research area. She just says to keep trying, and to not lose heart.