Afellay is on-loan at Schalke this season.
"It's really bizarre how this injury has gotten to me," he told Sports-Promotion.Nl.
"First my ligament injury at Barcelona, then my tendon injury in my upper leg. In the last eighteen months, I have spent more time recovering than playing.
"I know I have to pull through and I will. But there have been moments I doubted everything.
"Of course I want to be with the guys at Schalke. Preferably, I would wish them all the best for every match, and I would be there when they play.
"That's just how I am. If you make a choice with something, you have to stick to it. With that attitude I chose a loan period at Schalke."