Yes I Recently Had A Cyst Under My Left Armpit

Yes I recently had a cyst under my left armpit that I treat with antibiotics. It's since burst and drained. Now I cannot stretch my arm fully straight up because of what appears to be a tendon under my pit. It feels and pain goes from my elbow up my bicep thru my whole armpit. It looks like it was attached under my arm and now popped off and creating tension.