I was actually in the exact same spot so I feel you, lol. I didn’t trust doctors and I still have trouble due to past issues. I see that you mention Signal, so maybe you are as paranoid as I was before.
I’m curious, why didn’t the dumb phone work? Since maybe you couldn’t answer to co-workers fast enough? I’m contemplating this since a few years but I’m afraid of the move for this reason 
It cost me 420€ to get diagnosed, but thanks to our social system, I got reimbursed a lot of this.
As for the cost of medication… You would probably get so productive that the benefit is far larger than the $.
I don’t know where you live, so it depends… In France, you can go directly to a a specialist doctor, I believe. In any case, that’s what I did and I had no problem.
If you need the approval of your local doctor, get it, otherwise, you can skip it. The specialist will tell you if you messed up by going to them, and at most, you will lose a few hours.
For ADHD and other “mood” issues, the speciality you’re looking for is “psychiatrist”. Not “neurologist” or “psychologist”. These person work on the same body part, but not exactly in the same way 
Whether online or not, it does not matter…
What does though is that you find someone smart.
Some doctors are not trustable and will make really terrible mistakes. There are tons of money stuff too… So, you have to make your research after the doctor gives you a protocol.
Yeah I know, it’s bothersome. You don’t have to trust your doctor at first; you can act like a gate-keeper and question their decisions. You don’t have to trust me either; hell; it’s even very probable that I made mistakes in this very message.
I have prepared the official ADHD-rant just for you. I’ll probably copy-paste it on other places . Enjoy your read!
ADHD rant
Here are some hard facts about you
- You are struggling with over-use of screens
- You have social anxiety issues
- You have a good hunch that you have ADHD
Note that these issues are self-defending because well, meeting a doctor requires talking to another human. You have to push extremely hard at some point to find a solution.
For each of my problems, there was this pattern:
- Suffer from the problem for a few years
- Finally understand that I have a problem, complain about it to my family and friends, but act like I don’t have any issue. I just deny it
- Finally come to the realisation that I have an issue. That’s the part where I think that my life is over and that I’ll never fix myself and be miserable forever.
- Find out that there is a solution after a bit of googling
- (optional) self-medicate, do terrible choices
- See a doctor, I think they’re dumb or not trustable (not especially the case - that’s just my character), but at least there is some progress
- See other doctors, I trust them more
- Work with them until I get a solution.
- Profit!
For me, the hard part with dealing with any illness is dealing with it in my head. It’s not like: “ho I have trouble concentrating, I guess I have ADHD, I’ll just call a psychiatrist”. Hehe… It’s more like a drawn-out battle with myself over a few years, then a few months of meeting doctors and paperwork.
Here, I’m trying to make yourself skip a few steps like other people did for me.
Maybe it’s not necessary, and you are perfectly fine. Maybe ADHD is a Hoax… I can’t tell. What I can tell though, is that ignoring an issue and not acting on it because of this very issue is dumb.
For instance, I have chronic pain and I didn’t want to see doctors because it was painful to go outside… Well… I had to push through. Now it’s still there but my life is so much better… I wish that I started looking into this 3 years earlier, you know?
If you don’t trust doctors, at least, trust the holy internet. So here’s an exercice for you: just type the name of any of these medication + “reddit” (if you want to feel smart, replace “reddit” by “pubmed”).
There’s a high chance that you find yourself identifying with random people online.
- Methylphenidate or Dextroamphetamine (ADHD)
- Propranolol (performance/social anxiety)
- Prozac (depression and other stuff IIRC)
- LSD (depression, and probably tons of other stuff)
- Cerebrolysin (depression, anxiety, tons of other neurological problems)
- Modafinil (narcolepsy)
Of course they have their downsides and I’m no doctor… I just want to show you that issues that feel like they cannot ever be fixed were solved by researchers decades ago 
.
We live in an age where problems that ruin a life are fixed by a few pills. It’s a pure waste to ignore them. Illness does not happen only to other people. If you have a hunch that you have a problem, it’s not forcibly you thinking too much about yourself.
TL;DR: it’s hard and maybe useless to fix your car’s A/C, but you won’t regret it when you finally take a trip!
