Many people struggle to see a Psychiatrist to get an ADHD assessment, maybe it's too expensive, perhaps there are long waiting lists, or maybe there is no one in your area who can help.
Whatever the reason behind you not being able to access medical help, there are still things you can do to help yourself deal with the situation.
If you want to do a self diagnosis for ADHD, I used this one:
https://www.additudemag.com/adhd-symptoms-test-adults/