"To put so much effort into a game, come away to Australia which is an extremely tough place to come and play, and to lose like that at the end is difficult to explain and put into words," said the Ospreys back rower.
"As players you try to do your best and all the players gave their all and to lose like that at the end is a bitter pill to swallow. It will not be hard to pick ourselves up because we are a group of players who always give their all.
"I would be lying if I said we were not absolutely gutted with the way the game went, but we are sportsmen and we have a game next week. If we can win next week it will certainly help with the pain of the loss."
Wales were leading when the hooter went in the last move of the game, only for Australia to get the try to snatch victory.
Wales had started well, turning the ball over the for two early tries - a reward for the work they have been putting in on their defence.
"We had been working a lot with Rowland Phillips on our blitz defence and for the first 15-20 minutes it worked really well - we shut their space down and did not give them time on the ball and they made a couple of errors," said Thomas.
"We managed to finish off some chances even though they had a fair amount of possession. It was a great start to the game for the boys."
There is plenty more for the squad to work on this week after Australia dominated possession for large periods of the game.
"We are very disappointed with the way the line-out went, we worked hard on it this week. We will have to reflect and look at the video, but it is key to have good set piece and we are disappointed with that area," admitted Thomas.