I wrote a rather long comment a little while back about my experience with getting diagnosed last year, with emphasis on getting medicated.
I've included the link below, but having skimmed it just now, here's some context that might make it more relevant for your specific question:
Thought there was something "off" for years, but couldn't put my finger on it. Last year, one of my wife's relatives got an adult ADHD diagnosis, and his description of his symptoms made something click into place for her. She found an online self-test and sent me the link.
I was mildly insulted. I didn't like that she thought there might be something wrong with my brain, but on the other hand she's rather good at reading people, and I wasn't about to brush off her suspicion just because I didn't like the implications.
Adult ADHD Self-Report Scale (ASRS-v1.1) (PDF)
Took the test, and I rated very high in most sections, although not the ones about not being able to sit still, feeling restless, etc. I started reading up on ADHD, and everything just made total sense. Everything that felt "off" my entire life was textbook AD(H)D.
I printed out the test and the evaluation key (the one I linked above is the same as the one I took, but formatted slightly differently), did the test again. Then I wrote a bullet point list of the things I had issues with, basically a comprehensive list of my symptoms and their effects on my daily life. I should probably mention at this point that I live in Denmark, and YMMV with the following, depending on where you're located. It's also worth mentioning that psychiatrists (and not psychologists) are the only ones that are allowed to give the diagnosis in Denmark.
Took the papers to my doctor, explained my suspicions about ADHD, showed him the test results and my list of symptoms. He referred me to a psychiatrist for evaluation. Had to wait 6 weeks for my first meeting — apparently, a large portion of my generation is getting evaluated in Denmark right now, because almost none of us were as kids. Basically, if you weren't bouncing off the walls (I wasn't), or if you were a girl (I'm not, but relevant later), there was nothing wrong with you.
Finally got to my first psychiatrist appointment. Talked about myself, she asked questions about different things, growing up, school, jobs, fault life, why I thought I might have ADHD, stuff like that. She then gave me a 20 +page questionnaire to fill out for our next meeting.
Filled out the questionnaire at home. Basically a ton of questions about my current life, and then the same questions again, but in relation to my childhood. Can't remember the name of the questionnaire, sorry.
Went to my next appointment, we went over my answers, and by the end she said "Well, you have ADD." I was very, very relieved. I was worried about finally having everything fall into place, and then have a professional tell me I was wrong. Luckily, that didn't happen.
I asked about the next step. Should we talk about cognitive therapy? Coping mechanisms? "Oh no, psychiatrists only diagnose and handle meds. You need to go find a psychologist for the other stuff. Are you open to try medication?" I said yes.
This is basically where my previous comment kicks in: https://beehaw.org/comment/544089
The only thing I'd add is that if you're a woman, the symptoms of ADHD can be drastically different than those experienced by men; my understanding is that the research on female ADHD is only just beginning to catch up, and you need to read up on female ADHD specifically so you don't dismiss ADHD because you can't make the "classic" symptoms (almost exclusively based on male research) fit.
Best of luck with your journey — whether you get the diagnosis or not, finding out either way is a relief. If it turns out you don't have ADHD, you know you should probably keep digging into the alternatives (some flavor of autism being a tangential avenue, but certainly not the only one).
I hope you find some closure, and hopefully get some tools to help you improve.
Speaking of tools, have a look at this awesome (and eloquently titled!) post by fossilesque@mander.xyz: How To Unf*ck Your Life When You Have ADHD, and maybe poke around /c/neurodivergent a bit. Good advice to be found, as well as good people for sharing experiences and advice. There's also !adhd-college@mander.xyz which is quite good.