Saturday night was probably one of the worst feelings I have had as a rugby player.
To lose the Test series a week early is devastating. It is up there with the biggest disappointments of my career.
There is nothing worse than that 'should have, would have, could have' feeling. That is how we felt last week and it is exactly the same this week.
Sometimes you come off the field and think in all fairness, they were the better side. But on Saturday we felt we deserved at least a draw in the end, not just for the boys who played but all those in the squad who have worked so hard in the last five weeks.
In the dressing-room afterwards there was just silence for a good 25 minutes. There were guys just sat there still in their kit, devastated.
The Lions were left "devastated" after losing to the last kick of the game
'Geech' spoke to us and said he was really proud of us, but apart from that we just didn't know what to do or what to say.
It was just a numb feeling really, as tough as they come.
I got a text from Gethin Jenkins later from the hospital, where he had to have surgery on his damaged eye socket, asking how much more we have to take this season.
We have lost to a late drop-goal with Wales in the Six Nations decider with Ireland, and in a semi-final penalty shoot-out with Cardiff Blues in the Heineken Cup.
And now a last-minute penalty to lose a Lions series. We haven't had much luck really.
I haven't seen it again on TV but I remember on the pitch thinking it wasn't a penalty.
It looked pretty innocuous, one of those 50/50 calls, as if it was happening in slow motion.
I feel sorry for Ronan O'Gara. He is obviously down but no-one is blaming him.
As soon as the ref gave a penalty, I knew what was coming. I was stood next to Stephen Jones as Morne Steyn lined up the kick and Steve said 'there is no way he is going to miss this'. It just seemed like fate really, as if we weren't supposed to win.
The crowd had been chanting his name during the game and he came on and nailed a couple of great kicks.
I feel sorry for Ronan O'Gara. He is a great guy and I have total respect for him. He is obviously down but no-one is blaming him. We should have tidied up the game before then.
I felt it was a massive turning point when it went to uncontested scrums. The front five were getting a rest at each set-piece rather than having to work.
Losing four players to injury in that second half is always going to affect you and having boys playing in unfamiliar positions in the last 10 minutes of a game that tight is not ideal.
In the second half they had most of the ball, but when Jaque Fourie scored that final try, I always felt we would score again and get back to at least a draw.
Steve nailed a great kick from the touchline and I thought we had done enough. We felt quite comfortable, but you have to give credit to the Springboks. At critical times, they nailed their kicks and took their tries well.
The momentum did change after Bryan Habana's try but it would never have happened if Brian O'Driscoll had not taken such a hell of a whack before that.
He banged his head first in the same incident where Gethin cracked his cheekbone as they both tackled Habana.
Brian carried on playing but didn't really know where he was after that. For him to keep going was incredible.
I was rooming with him and he was tucked up in bed by the time I got back on Saturday night.
We just went back to our hotel and had a few beers, feeling sorry for ourselves. It was quite sombre really, as it felt like half the side were in hospital.
It still hasn't really sunk in yet. We still have one game to go but we have lost the series.
We are heading off on safari to get away for a bit, which is ideal. Hopefully we will enjoy that and then probably come back to training on Tuesday.
We still have a huge Test coming up. Obviously a few boys will be ruled out with injuries but there are others who can come in and do a job.
It is still a Lions Test against South Africa and we will give everything we can to win.
Even though the series might be over, we have gelled so well on and off the field, no-one wants to be part of a whitewash.
Martyn Williams was talking to BBC Sport's Bryn Palmer