I Don’t Know If This Is UK Or US Based

I don’t know if this is UK or US based but I guess it doesn’t really matter. I’m 27 and female and I have some really bad attention problems. I was academically gifted at school and did well at university and everything; it took A LOT of work to get thru that because I struggle so much to concentrate, i get distracted and i’m dyslexic. It’s really hard to actually get a doctor to take me seriously now though bc they assume bc i’ve done well that there’s nothing up with me. I work as a copywriter and web designer so it’s not like i don’t need to concentrate for that. what do you think i ought to say to make a doctor take me seriously? is it possible i’ve made it all this way with undiagnosed ad(h)d?