Hi, sound like you've had a huge amount of horridness to deal with. I'm sorry you've been treated like that. If I were you, I'd keep learning about the condition and see if it applies, before committing to spending all that on it. I took 6 years to research and soul search before dciding to getting a diagnosis that, let's face it, was more than I could afford (I'm still paying it off) but, I'm glad I got mine, in the end. To me, my diagnosis completes me, in a weird way. It validates me, because even though I too, suffer from living in a body that is traumatized and diagnosed with a traumatic stress disorder (complex, developmental PTSD) and I felt like a failed human, plenty, in my life, it turns out, I'm not a failure, of a neurotypical human, I'm brilliant, amazing Autistic human.
So, in that sense, pursuing a diagnosis can be very validating for some of us, but, make sure you're sure that it fits, because it's a huge financial commitment, for the most part.