Mother!
Carlisle was just walking when he saw what he thought was Edward being bitten by himself. Edward saw this when he was testing his telepathy and ran to Carlisle making sure he was alright, unfortunately he wasn't...
Everyone was upstairs to see if Carlisle was ok, but they saw that he was screaming and attempting to run away. He was being held down by Emmett and Jasper; they had to do this for his own good. In the end they had to take him into the library, so Renesme didn't see that. They kept Carlisle down, but then Edward saw a vision of him giving his mother the Spanish influenza which killed her. He started screaming and trying to run away, they took longer to get him down, Alice and Rosalie had to come up and help. Alice and Jasper got Edward down, Rosalie and Emmett got Carlisle down. After a couple of hours they both had calmed down enough to stop being held down. Jasper had stayed and used his talent and sent out a calmed mood in the room. Carlisle and Edward both didn't come down just stayed in their rooms not talking to anyone. On the Monday after the family decided that Edward and Carlisle both needed to stay home, they didn't even argue or talk.
After a couple of weeks of being at home they were a lot better, and then Edward went back to normal, and Carlisle went back to work. They both explained that they were acting depressed, and seeing things, so might go home at any point. Emmett and Rosalie went with Carlisle to work, and then that left Jasper, Alice, Esme, Renesme and Bella at home with Edward. Exactly 3 weeks after the first time it happened again, unfortunately Carlisle was at work, and started screaming but Emmett and Rosalie had him down in normal human speed. And dragged him to the office, all of the doctors came in and checked on him but still saw him trying to get away and screaming. They asked Emmett and Rosalie if they want him being treated or to be taken home in an ambulance, they quickly said "Yes" to being taken home in an ambulance. The paramedics drove them back home while Emmett and Rosalie held down Carlisle, but Edward was having the same thing happening to him, Jasper and Alice were holding him down when Carlisle was brought in and placed in the library with Edward. It took longer for both of them to calm down but they did in the end, they only stayed in their rooms for a week, but they went back to the way they were nearly. When Carlisle went back to work he wasn't quite right, and got lots of concern from the other doctors, who wanted him to have a psychological assessment. As much as he tried he couldn't get them off his back, so agreed to have one. As he had found out that vampires can have tests and x-rays. The only one they can't have is ones not including injections. All of the family weren't so sure about this but they thought it might help as he was acting less like he normally should. When he did the test, it took 2 hours for him and 30 minutes for the rest of his family. Carlisle booked Edward in for a psychological test too. When the results came back the next day, everything was fine, but they had suffered depression to a very serious level. Carlisle was told to have as much time as he needed to. So he could get himself sorted out, he kept trying to come back but every time he thought it, he would be told no and to stay at home. After another 6 fits or as he called them seeings, the family didn't trust them to go anywhere by themselves.
After 2 months Carlisle went back to work, and was fine but no and again he saw her and just managed to whisper sorry to her. The other doctors were always careful not to mention anything about it, or ask him anything. All the time they asked "are you okay?", but Carlisle got used to this and let it happen.