I had almost the same.
For me 6 weeks total rest helped a bit. Then started to play again and the tendon got inflamed. Now, 3 months later, after loads of exercises/stretching by a physiotherapist i am able to play again. but still mis 10% of my motion in both ways.
- make sure you really dont stop using your arm. so get that cup, do the laundry etc. worst effect will be that you develop an minor/major frozen shoulder. then you are even further away from the tennis court.
- icing, but also ibrupofin or something when it inflames. without any hesitation. it leads to impingement and that is really nasty..