Pain in forearms / hands

I had debilitating pain in hands and forearms due to typing. I was going to have to quit if I didn't find a solution. As long as I work this job, I still have pain 365 days a year, but it's now manageable. A few things from my limited, humble experience:

1. Everyone has different, idiosyncratic issues here. If you google this, you will find plenty of stories of people who could not even turn a doorknob after the pain was so bad and they had a miracle cure - and their solutions are nothing alike. There are different causes even when symptoms are similar, including nerve issues. Because of this, it's useful to see a professional. Also, for some people the pain is just sort of a nuisance, and for other people they go from being fine to qualifying for disability in a matter of weeks. I was closer to the latter, but prioritize accordingly.
2. Even from professionals (and scammy non-professionals), there is a lot of "we don't know" and also people claiming they have the definitive answer. Do not expect a precise diagnosis and be skeptical of any silver bullet. Personally, PT type exercises worked wonders for me, and professional help here made a difference.
3. Ergonomics matter. I thought something like desk height hurting my fingers was bullshit, and I was wrong. I use a mouse where I click with my thumb and my keyboard is split; you will find people where these specific things didn't work. Find what works for you. Perhaps more importantly, you can also find things that cause a lot of pain and avoid them (e.g., my laptop keyboard causes me tremendous pain in a short amount of time). 
4. Related to #3: the most important piece of equipment for this will be your keyboard. Don't hesitate to spend - I have a $200 keyboard sitting underneath my bed and I think it was worth it because I got to try it and the $150 keyboard I am using; one of them worked. For me it was money well spent.
5. Experiment. Everyone's problem is different, and everyone's solution is different. Try cheaper stuff first. Stretching, exercises, massaging pain points, adjusting seat height. Then a new mouse, different keyboards you might have lying around, then work your way up; ergonomic keyboard models, braces, a good chair, a new desk. But I think you should try lots of things and see what works.
6. Healing takes time, and the problem is never gone - you will have to manage it for the rest of your life. In this vein, be patient.
7. Do not wait to do something. I repeat, do not wait. There will be a lot of uncertainty, but one thing I can promise: it will get worse. Maybe it won't be so bad that it's really a big deal for you, but for some people it's literally life changing (and not in a good way). If you think there is a chance you could be in the bad bucket for this, don't roll the dice.
8. Good luck