Zap is right, PATIENCE. For many folks years of inactivity, poor eating, bad habits, injury, stress, etc all add up to a body that can take just as long to recover.
Take your time,learn to listen to your body and what it actually requires.
At forty I was htting the gym constantly, bench pressing about 300 lbs but my shoulders were both in constant pain. I've since realized that they are much happier doing 4-5 sets of 40-50 reps of good, strict, close-grip pushups.
It doesn't take much to be strong and fit when one finds what works.
It sounds like you have solved your problem for now. A consideration for the longer term is perhaps move into a martial art that employs more circular movements instead of linear strength against strength.
Have you tried Sauna and Cold plunge? Not only will it help in muscle recovery and healing, it will increase your cardio, heart stroke volume, plasma volume, red blood cells etc.
If you are in North Idaho hit me up and I'l take you thru an experience