Seeing one relationally oriented therapist and "reading rather a lot about therapy" does not make you any sort of expert. Let's get real. I think you're really standing in your own way. You are so unhappy with your life and you have said you feel hopeless that you're ever going to have the things you long for, but it seems like you aren't very willing to tolerate any discomfort in therapy. Getting validation and warm fuzzies is all well and good but the fact that not getting these things provokes such an immediate strong reaction in you makes me think it could be useful for you to learn to withstand working with someone who doesn't see it as their purpose to provide you with those things.

I know you made a post recently with something about client wants being pathologized. I'm going to be completely blunt. While I don't think it's at all pathological to have preferences like yours, I do think it's indicative of something that you respond so strongly when you don't get what you want in this area. You develop really detailed narratives about these therapists, seem to think that they are objectively wrong, and cognitive distortions run rampant (mind-reading, black and white thinking, personalization, etc. etc.).

I hope you decide to go against your inclinations and give this therapist a chance. I think right now your mind is already made up and unless you commit to yourself to actually giving it a go for real, you're just wasting your time because you're not even open to letting her be helpful to you.