Hi Mira
The majority of pains like this are soft tissue related, but not necessarily soft tissue where the pain is! If you have pain on flexion/extension resistance, this may mean the muscles of the forearm are unable to perform fully as their fascial sheathing may be tight around them. This has the effect of 'strangling' the muscle and as a muscle needs all it natural space to work in, it will become weak to a degree if not. What you feel in the wrist is often the compensation for this weakness, ie overuse of local intrinsic muscles and muscles not normall used for flexion/extension. This overuse stresses these muscles and related fascia thus pain occurs. If you have limited ROM in flexion/extension this will be further proof of fascial tightening. You will need some myofascial release done to the forearm fascia to release this, thus allowing muscles to work correctly, which then reduces the need for compensation, thus no pain. It will be very unusual for a joint to be the cause in something so acute...remember joint movement depends on soft tissues giving them the space in which to work.
Try that
Hope it helps
Pete