Scepticism in BPD and ASD diagnosis - looking fort certainty and closure

I am a trans woman who has been diagnosed with complex PTSD and BPD. I have a long history of anxiety, depression, poor sleep patterns and general poor physical health due to the previous points, making good self-care an uphill struggle.

Since moving out of central London into the countryside, I have turned my life around by avoiding London, social situations, and anything that elicits strong emotional feelings.

Ever since the start of Covid lockdowns and an awareness of the autistic diagnosis of others close to my family, I have become more aware of some of my own autistic-type traits. I consequently sought a referral through my GP to be assessed for ASD. I continue to be on that waiting list a year later.

I have recently paid for and completed a private assessment, which has diagnosed me with ASD. Since that diagnosis, many past life experiences, situations and memories have started to make more sense in that context.

I am, however, sceptical of the diagnosis because I believe I may have unconsciously led the diagnosis towards a specific conclusion as a result of my BPD, despite my ASD diagnosis claiming that my BPD diagnosis may well have been a misdiagnosis.

I found https://embrace-autism.com/its-not-bpd-its-autism/ on another forum post.

I naturally distrust my own thought processes and motivations, just as I am naturally sceptical of an NHS ASD assessment (in my mind they're motivated to not contradict a previous NHS diagnosis of BPD, and are motivated to be more cautious with an ASD diagnosis), and similarly I imagine that any private ASD assessment would be motivated to provide whatever diagnosis they believe their client may be more receptive to.

Do I really have BPD? Do I really have ASD? Do I have one and not the other, neither, or both?

I have quite a complex history, but I would really like to feel like I can truly trust and believe in a diagnosis, and know once and for all feel that my circumstances are reliably professionally understood so that I can get the more appropriate therapeutic help or self-learning so that I can manage day to day life better. I really wish that I could step into an episode of "House" and have some kind of conclusive closure and certainty.

I'm wondering if anybody else has or is experiencing any of these thoughts or complications. I feel sure that it can't just be me.

What's next? Do I shell out for another private assessment and just make sure I lay everything out again? Is that just a waste because I'll never get anybody to look at everything holistically, and regardless, the NHS will refuse to recognise any private assessment?