Desk looks fine but don't expect it to solve your problem
First of all this is amazing, I have joined this forum for help with my printer and thought I would be able to contribute nothing but this is actually something I can provide good advice on as I am an ergonomist.
The desk looks fine. I am assuming it is height adjustable and that the keyboard tray is also adjustable. There doesn't seem to be a lot of space to put your work but if that doesn't bother you it is fine.
It is probably not so much pressure on your arms which is causing the problem, but the position of the joints, that is the wrist and elbow. The elbow should be bent at around 90 degrees and the the wrist should be fairly straight. A wrist rest may help. You also need to make sure that you chair is adjusted correctly. Your hips should be at around 90 to 110 degrees (110 degrees meaning you would be slightly reclined). Your knees should be flexed at around 90 degrees and your feet should be flat on the floor.
Make sure you are taking regular breaks, at least every 45 minutes to stretch your shoulder, elbow and wrist especially on the painful side and your neck.
If you keep having the pain you may need to see someone about it.
