Greg just stood there for a few seconds, tightly holding onto Sherlock who was really leaning on him now. He tried to get a glance at the other mans face, noticing that his eyes were close. Then he carefully tugged him towards the door. "It's not far. " he said softly, though he was well aware that this was Sherlocks home and that the man knew anyway. "You can sit down and I'll get you some tea. " he went on, feeling as if he should be saying something.
It took a bit, but they made it to the couch, where Gret made sure to carefully set him down and let him lean back enough to take the pressure off his ribs. He grabbed the blanket that had been folded and left on the back of the couch and covered him with it. "This alright?" he asked, to make sure. It was a little strange to see Sherlock like this. He had not even been so weak when he'd had been sick with the flu. Even then he'd been complaining of boredom and roaming about and Greg had barely managed to get him into his bed, or lay down anywhere. 
He turned around and got the tea, a bit hurried maybe, so that he wouldn't have to take his eyes off Sherlock for too long. He said down on a chair by the desk to watch him and then, carefully asked: "Should I call John?" He wasn't sure about this. John was probably the only person Sherlock really trusted, but the way the detective was, he might not want John to know anything about all of this at all.