First of stop typing. If you are sure you have tendinitis, the general regime is rest, ice and anti-inflammatory drugs. You need to see a doctor to get the correct dosage as it is weight based. Generally hands and wrists are splinted to avoid unnecessary movement (I used to be an epee fencer and spent my share of time in them). Once the swelling is gone you need to re-learn how to do whatever caused it in a different way to avoid a repeat.

David Warren
From the Pacific Northwest
Where swimming is an indoor sport