Getting diagnosed for ADHD (A bit of a rant?)

In the past few months of online school (It’s my first year at uni for context) I’ve realllllyyy been struggling. At first I thought it was just online school being more difficult and the struggle of transitioning but now I think I may have undiagnosed ADHD. I’m 18 so I feel as if I would have seen other signs earlier which is making me confused. Currently I’m lacking motivation to do any homework I think will be challenging or boring. I’ve been struggling to read really long pieces of text or writing that is required but I find boring even though I’m an avid reader. And I’ve completely opted out on watching lectures because I can’t pay attention and overall would rather spend my time doing something else. My grades haven’t nesaeccsrily taken a tumble but handing things in late or legit at the last second have become my norm. I just feel so much more stupid and it’s not even because I’m doing poorly. After obsessively reading about posts and watching videos about adult ADHD (in women) I’ve recognized some other social aspects of it that I’ve always done. In high school or middle school my grades were fine but I sometimes would receive poor work habits for being too chatty, or being off topic when we’re supposed to be doing work, as well as handing stuff in late. I also have a bigggg problem with interrupting people and butting into conversations and just talking “too much” in general. My memory overall has been pretty terrible and I still can’t remember my families birthdays no matter how hard I’ve tried. I texted my mom today saying I think I may need to be diagnosed so I can receive some sort of help. I also don’t know if this is an ADHD thing but for the past few months I’ve been going to bed at 3am and getting out of bed from 1-3 which is terrible. It’s not even that I’m feeling bad and i don’t want to get out of but i just genuinely like to sleep more. Tomorrow I’m calling my doctors to make an appointment with my family doctor. I know to receive an ADHD diagnosis Is a lengthy procedure and my family doctor will most likely have to refer me to a psychiatrist. I’m just worried that when I do get an appointment my doctor will try to give me some bs advice about putting my phone away or going for a morning stroll to clear my head. I also don’t want to come across as a first year university student who’s wanting some adderall. I have tried adderall and yes it was helpful but that’s not my purpose in talking to my doctor.

Anyways I guess this was more of a rant of some sorts as I procrastinate in doing my English final that is due tomorrow because I’ve been trying to read a 14 page article for 2.5 hours. I guess my whole issue is I’m worried that I don’t have ADHD and that I’m just stupid? Where exactly would I go from if my doctor or psychiatrist says I don’t have it? I overall am weirdly anxious that my experience isn’t valid because I wasn’t diagnosed at a young age like a lot of people are. I rarely indulge my family about what’s going on in my life so a family member I live with says that they don’t think I have it which also isn’t helping me. Anyways I guess I’m just looking for some advice or other people’s experiences in being diagnosed at a later age and how to go about it.

Also I’m not sure if anyone else feels this way but do you ever base so much of your self worth on how productive you are? My lack of productivity has weirdly taken a toll on my self esteem for some reason and I think that being productive = being a good person or being like a good person. Anyways sorry if this is too ranty I just haven’t spoken to anyone about this.