Love your forest sketch, it really communicates a lot with big shapes! I read the wolf as being her pet and just ahead of her in shadow, so maybe overlap his tail clearly over her so he is clearly in the foreground.
As for your hand, I've been recovering from an weightlift injury, and I've found the best thing is a physical therapist or someone like an osteopath who specializes in sports injury/RSI. You are absolutely right when you say "STOP" because you can really extend your recovery time if you do too much damage.
Tips to help aid recovery:
(If it hurts immediately)
Submerge entire forearm in icewater(mostly ice tho). You can use a sink, tub, or even a water pitcher will work. Consciously tell your hand to relax. Part of the body's response to pain is to tighten up the affected area, which further compounds the problem because it makes tearing of the tendon sheath more likely. Icing is a great natural anti-inflammation method, that also dulls a lot of pain, and squeezes out old blood, dead cells from the inflammed area.
Dip for 8-10 seconds, no more. Dry, wait a few minutes, dip again. You can do this as often as you want, but frostbite is a genuine concern here so don't go overboard. In the beginning, I was dipping several hours during the day, 10 times an hour. You can choose what time(s) of day work best for you.
A quick alternative is to just wrap an icecube in a towel, or icepak, or whatever, and run it up and down your arm. You'll feel everything kinda squeeezing and freezing. You want to stop when the skin turns slightly pink.
Something that's been working really great for me is combining heat with ice dipping. After I've dipped my arm and it's still cold, I run hot water over my forearm and wrist for about 20-30 seconds, taking breaks if it gets burning hot. Then, running back to the kitchen and doing another ice dip. Heat helps blood circulate and bring fresh oxygen/nutrients to the affected area.
Ideally, the icing should take care of most of the pain, then you can warm up the arm, and do some very, very, very light stretches. Arm out straight in front of you, bend back wrist gently, bend wrist down and back gently.
Eventually, you shouldn't have any pain when resting, however you may find it flaming up very quickly after you start to draw. In my experience, and working with my physical therapist, I have had to slowly rebuild the tendons using 1-2-3lb weights, icing if it hurts too much. My physical therapist spends about 30-40 minutes massaging the tendons, and breaking down scar tissue that has formed, and in the beginning it can be really painful, but eventually it just feels so much better. Even though your not hurting when resting, all it takes is a gentle prodding around your forearm, and you'll find areas that are still very very tender. These should be healed as well, so it's good you're seeing a doctor!
Hope this helped! I think I'm going to copy paste this, and start an official RSI thread.