The 35-year-old could become the first player to top £2m in prize money in a single season if he wins the world title, the prize for which is £500,000.
Trump, speaking to BBC Two, said: "Shaun was in a world of his own for four or five frames and I was a little bit worried, but I had to back myself in that last frame.
"In the past I've been a bit hard on myself but I'm a lot stronger mentally and I've learned to appreciate the losses and use them as motivation.
"I'm a lot more confident this year, I'm hitting the ball a lot better. I probably have a bit more belief in myself and I feel a lot more calm."
On his chances of winning a second world title, he added: "Pretty much every single day [you play] now you are looking to that next session every time.
"It's only going to get tougher, we're not even halfway there now. It was an extremely tough draw to be playing Shaun at this stage, with the form he was in."
More to follow.