How much more hassle? Went for breast implants in 1985. Lived through fear of foreign body, hardening. Now dealing with sagging. What next?

Depends. I sense your frustration and appreciate that you don't want anything else done. It really depends on what you are looking for . You can choose to do nothing or see a very experienced plastic surgeon who can treat your capsular contracture, exchange your implants if necessary, and perform a breas lift if required. Call me if you like.
Implant Hassles? Impossible to give you good advice online. I'm sure you are aware that breast “sagging” is not necessarily related to the presence of breast implants, but may occur with aging, pregnancy, weight gain/loss. For accurate advice, seek consultation with well experienced board-certified plastic surgeons in your area.
You need more info. Unfortunately implants are not forever. I feel as if you have not been adequately counseled or may not have realistic expectations. With or without implants, it is likely that you would have experienced sagging. Did you expect that the implants would prevent sagging? Removal of the implants and allowing nature to age the breasts may be your best solution. However, many other option exist ....
Sagging breast. With age , people may get sagging(ptosis) of the breast. It may not be related to the implant. You may need abreast lift (mastopexy).