Question: 27 year old thinks may have Osteoarthritis or…

So I’m wondering if I’m developing Osteoarthritis, Cubital Tunnel Syndrome, or just a RSI.

Relevant background information:
I’m 27 years old, a computer programmer, and I play a lot of video games with a keyboard and mouse in my free time. My grandmother on my mother’s side has Osteoporosis.

Symptoms:
A few months ago after a couple 80 hour work weeks, I started having issues with my elbow. For awhile, the right side of my forearm, my ring and pinky fingers were feeling almost stiff (I don’t really have a good way to describe the discomfort), and occasionally my pinky would experience tingling, numbing sensations. On occasion, my elbow would suddenly lock up, and when I moved it, the unlocking process involved sharp pain and a large crack right at the joint.

After the long work weeks stopped, the pinky/ring finger issues went away, my forearm has mostly been less stiff, but the occasional elbow issue still occurs, just less frequently.

Now, in the last month or two, my hands have started cracking a lot (numerous times a day mostly in my thumbs), my hands feel stiff a lot, and ache on occasion. I’ve also had a lot of other bones that never normally crack (like my knees, shoulders, hips, etc.,.) start to crack a few times daily as well. My wrists crack profusely (although that’s not new), but ache quite more than usual.

And although I’ve been worrying about hand weakness on and off for years, (when I laugh really hard, I lose the ability to grip objects I’m holding or make a fist for a few minutes after), I’m having a hard time opening water bottles lately to a point where I need to ask someone to open it for me. Yesterday I even had to have fiance open one of those little clear capped ones. The kind that you sometimes accidentally open if you put them in your bag and the friction of moving around alone can cause the contents to spill out.

And a few weeks ago, I was at the doctor’s office and they wanted me to fill out forms on paper, and granted, I know in this day and age we write so little that of course our hands get tired after writing a lot, but my hand got so weak it actually “crumpled in” around the pencil after the third or fourth page, like I couldn’t even hold the pencil anymore. And arguably, it wasn’t like I was writing a paper, it’s writing a few sentences here and there explaining things and checking boxes, but my hand didn’t have the strength to finish.

But – again worth noting, the elbow that cracks is on the same side as my writing hand.

I did do the paper grip test at home a few months ago, and again today, and passed just fine. So again, I’m wondering if it’s CTS causing hand weakness, why am I not having issue with the paper?