SO glad to hear from you Ribit!!
Rest my friend. You need it. The body at your age and my age and DG's age takes longer to recuperate and recover its strength.
You're a Marine so you know how to deal with pain. Ignore it until you finally can't.
My Church will be praying for your recovery as will I continue. Get well and DO the THERAPY exercises.
Warning: They will HURT. At first. They will get easier and better as you make progress but shoulder surgeries are rated at the top for PAIN after surgery and during therapy.
SO many muscles wanting to scream.... Yes sir!
Semper Fi!