There are several recent threads on GE & TE.
"guessing its just a strain" ?
"A strain is a stretching or tearing of muscle or tendon." From -
If you just tore a tendon it is important to stop playing or otherwise stressing it immediately while the tissue is starting to heal. You run a risk of developing a chronic GE or TE injury if the tendon tissue heals in a defective manner on the microscopic level. See recent threads.
Best to see a well qualified Dr.
Both the best man and woman players in our tennis club are each currently dealing with recent TE injuries.