yep - it will return
I took a year off from illness and am still ramping back up toward peak fitness - notice I say toward - as I have no idea if I will ever return to race form - and if I don't that is ok too.
I have found that with limited time - quality riding is more important than quantity - I do intervals alone and this works best for me - when I want to socialize I ride with others without any agenda or goals - this gives a nice balance. I believe your body chemistry changes after a prolonged illness - especially if you had to take a lots of meds like I did - and patience is key. The way I feel after finishing a ride is priceless - fast, slow, long or short.
You have done the hardest part by getting back on - now "enjoy the ride" It really is all about the journey.
"Character cannot be developed in ease and quiet - only through experience of trial and suffering can the soul be strengthened, ambition inspired and success achieved" - Helen Keller