Benefits of add/autism diagnosis

Hi, I (29f) was wondering if anyone got a diagnosis for adhd/autism as an adult and if getting a diagnosis has any benefits. The reason I'm asking is because I keep running into the same problems (hypersensitivity, fatigue, migraines) that leave me unable to work full time. Right now I work 50% and even that is too much for me. My partner and I suspect there might be autism or adhd at play.

We did some research and found that most diagnostic centra are either expensive (>€1000) or have long waiting lists (3 years).

This makes me wonder if getting the diagnosis is worth it. Do you have any benefits afterwards eg. reasonable adjustments at your workplace? Or is it just an explanation of why you are unable to fit in and that's it?