I'm in the USA, so take that into consideration. On top of what everyone else has posted, from what I have read from UK users is that the first major hurdle to a diagnosis is getting the referral from the general practitioner. Often times, that doctor will had a distorted or incorrect belief of what an "autistic person looks like" and gatekeep the process. That's not to mean that you have to fight them or not. I don't know what to do in that case. However, if they deny the referral, it doesn't mean you're not autistic. I don't know what the proper way of overcoming this hurdle would be, so maybe others with experience or knowledge on the subject could share their recommendations. If you don't get any, please make another post. There are surely others that would benefit from that information.
In the meantime, here's video relevant to my comment: https://lemmy.world/post/7746510
Edit: Good luck with the process and let us know when you find out the results either way 🙂