Don't give up. It looks great. Just have a break from it and come back to it. One of the best examples I've seen of that truck. I've built 2 of them, one out of the box and one converted to an Australian T904 Kenworth. Yours looks better than mine. I'm about to tackle a prostar after I try a tamiya laferrari. That's been a learning curve as I'm more use to building trucks. The last car I successfully finished was about 2 years ago, it was a tamiya Nissan 370z. Cheers.
Ben