I need some help telling (and convincing) my parents to at least get me tested for adhd.

I have been trying to prepare for a couple tests and do a bunch of work, but I just feel like I cant do it. I sit down to do it, and then just start watching youtube while thinking to myself “I should really start working,” but I just never start. My parents say it is because I don’t want to do it or because I am really lazy, but it doesn’t feel like that anymore. Am I really lazy or do I actually have adhd. I really need to know because I somehow have to fix it in time so that I can actually study.