(might be a VERY unpopular opinion) med, health related PSA | long toot
Self-diagnosis is okay.
Looking at the ICD/DSM, talking to people diagnosed with it, researching and *finding that this is what your life is like* is okay.
You don't have to go to a doctor, you don't have to experience every single minor symptom, you don't have to "always had it". No.
If you find something that explains everything perfectly and that is what you need, then diagnose yourself.
If you need specific accommodations, talk to a doctor or otherwise medical professional, because that's something the system needs. If you find that their advice isn't helpful, talk to the next one. Talk to everyone until you find someone who understands.
I also don't always have the energy to follow that advice, but it still influences my way of approaching the journey to health.