How To Treat The Pain Caused When Bending The Wrist?

Hello. I have had pain in the top of my wrist when it is bend forward with my hand open. The pain has been apparent for about 2 weeks. It does not hurt if I make a fist and bend it forward (toward the forearm). I play alot of guitar and the pain is very apparent when making barre chords-which puts my wrist in the same position as bending forward with my hand outstretched. Also there is sometimes a very minimal click or pop (no sound really, just a feeling) when bending. So the pain is on top primarily, but I did do some weight lifting last two weeks ago and it move the pain to the entire wrist top and bottom to where I could not move it much. After icing and limited motion, the pain subsided, but has returned to what I described above. I am thinking it could be tendonitis, because the pain is on top. Any ideas? How should I go about treating it? I am hoping to get back to playing guitar soon. Thank you for your help. Matt