Should I have surgery to fix a rotator cup with full thickness tear at 58?

[retiree58]

I injured my rotator cup over 10 years ago doing gardening. In 2010, an MRI of my right shoulder showed a small surface tearing of my supraspinatus tendon. Then in November 2016, another MRI showed a full-thickness tear of the same tendon with 1.4 cm of tendon retracton and mild to moderate muscular atrophy with associated moderate subacromial subdeltoid bursits. I still have about 80% functional movement of my right arm but it does hurt a little at certain positions. I have read about the pros and cons of the rotator cup surgery. Currently I am waiting to normalize my thyroid (out of range at 6.8) before I can have the surgery. I am female and 58. I am wondering what would happen if I don't have the surgery. I was told that the atrophy will be worse and other tendons would be affected as I age. I am retired now but my right hand is still very important to me. Can someone kind enough to share their opinions and/or experience?