Lodem,
I also operate with a Med. Dec. but fortunately without any complications at the moment. However, when I read the new regulation as it applies to you I cannot see the problem:
For the purposes of this article, “disqualifying medical condition” means any physical or mental condition or illness, or any history of such a condition or illness, including—any surgery or medical treatment that might impair the safe operation of normal flight controls or render the licence holder unfit at any time to perform any function for which the licence is granted.
If you have been safely operating the controls for 20 years since your operation, and signed off by your GP, it cannot be described as a disqualifying condition under this regulation..