The Royals were undone by an injury-time winner from Gareth Barry.
Karacan, who had been making his first appearance in two months after overcoming a knee injury, said: "We're gutted, the boys are devastated.
"On another day, Tabby gets a penalty and we get a goal to take the lead. We just don't seem to get the decisions when we need them.
"The boys have been unbelievable, we all worked so hard.
"Yet we defend for our lives for 90 minutes and they go and get one in injury time even though everyone can see it's a blatant foul.
"You look at the replays and he's all over Shorey. Nine times out of 10 it's a foul - but it's not gone for us.
"People are writing us off day in, day out, no-one is giving us a chance in hell.
"But you can't take notice of it. The fans were fantastic and, as players, we look around our dressing room and we have faith in each other."