The system is that licenses are 'suspended' whilst you are medically unfit to perform the privileges of that license. I have had a suspension twice due to a badly broken leg took its time healing and then due to having to take medication for glucose intolerance . On both occasions the CAA medical staff were very helpful and understanding.
Getting the license back was a matter of exactly following the medical regime outlined by the doctor (consultant/whomsoever) and making sure that any targets necessary as advised by CAA were met. Paper confirmation is absolutely required to prove that these targets have been achieved. Onc e this is done and confirmed to the CAA then an assessment is done by them and the suspension lifted. NB.!! If you are sending documented information to the CAA by e-mail it is worthy of note that they have a 24hr 'sterile e-mail' system in place where your mail is placed in a safe 'vault' which is virus proofed before they get to it, so sending anything on a Friday or after midday is going to incur a delay. The way around this is to fax the details and back up with originals in the post.
I have known people be off for more than a year whilst recovering from the like of cancer treatment and not have their license removed, only suspended.
I hope your fears are unwarranted and things go well.
(Should you need to talk to someone please feel free to pm.)