I'd suggest going to a pharmacy ( or Walmart) and getting a wrist brace--they'll cost between $15 to $30.
As a cartoonist, when I was working as a inbetweener in animation, I used to get wrist and hand problems frequently. The reason was that I was always elevating my elbow when I drew and thus it was affecting my arm in both directions. And the pain was BAD. I'd have to wrap my arm in a heating blanket each night, and endure the spasms as the muscles tried to sort themselves out while I slept.
I used to slip my arm into my t-shirt sleeve, up to my elbow, in a kind of make-shift sling. Tried all kinds of stupid remedies for it ( without seeing a doctor) and one of the one that worked for a while was taking a small full soup can, and resting my arm on a tabletop while rolling the can up and down my arm.
First few times are brutal because the muscles are tensed and all screwed up......so the arm flops around out of reflex.
For me, the symptoms and discomfort mostly eased off over time, as I switched to other kinds of drawing, but the problem reoccurred after years of computer use.
See, I'd have my mouse located in a spot where I'd have to suspend my arm and elbow, and sure enough.........I'd get the numbness, tingling and aching all over again. Not all the time, but occasionally.
I bought a Futuro wrist brace, basically a plastic splint inside a durable vinyl/cloth gauntlet, with velcro fasteners to tighten at the knuckles, wrist and forearm. The splint lays on the underside of the arm, ending in the palm of your hand.
Combine that with some (optional) pain-relievers or muscle relaxants and it's always worked for relief. Now, I wear the brace for a couple of days, maybe a couple of times every couple of months.