I cant even jog to the end of my driveway, if it makes you feel any better, LOL just walking that far can sometimes be a challenge (my driveway is almost 200ft long)
but yeah, getting them to listen is sometimes very hard..
I would start by sitting down and making a list of all the symptoms you have and when they started.. pain and where it is located, how often and how bad; the brain fog; fatigue, digestive issues? sleep problems? edema? depression and/or anxiety? all of it. write it down! (You can find a copy of that test in pdf form and take it with you, but not sure i would lead with that item)
Start the symptoms list now and every time you think of something, add it to the list, so by the time you go to your appointment, you have at least 85-90% of the symptoms noted.
Then, when you go to see your doc, just tell them "there is no way i should be feeling THIS bad at my age - there HAS to be a reason for it" then hand them the symptom list...
This is what I did with my primary.. and that was when all the testing really got started - was tested for Lyme disease, RA, Lupus, psoriatic arthritis (psoriasis runs in the family) and so on... blood work to check vitamin & mineral levels, hormones, etc. x-rays of various things.. lumbar spine, cervical spine, hands, etc.. also had an MRI of one hand, to get a better look at the joints - I have osteoarthritis, but they wanted to make sure there was nothing more serious.
When it was all said and done, I do have osteoarthritis, pretty much all over, but with the fatigue, ibs, sleep problems, wide spread muscle/tendon pain, etc.. there is really only thing that can cause all of that after ruling out other more serious problems.. and that is Fibromyalgia.
And, in the midst of all of this testing, and PT, and treatments on my lumber spine to reduce arthritis pain.. and trying several different meds (and trying to wean off one that resulted in withdrawal symptoms) I came down with a kidney stone and all the fun that entails.. yeah.. has been a rough year!
but I am still here, still kicking and still fighting the fight.