The forest seemed endless. Either that or we were going in circles; it seemed like the same trees kept passing by, like the looped backgrounds in old cowboy chasing scenes. Just as I was about to lose hope, though, the trees cleared away, and Tom and I found ourselves in a small valley.
Two people told me that I don't need the though. But, I don't know, I feel it's necessary to add one, because the sentence is saying: "We were going in circles and I was about to give up, but I finally didn't because we found our way out."
Or maybe I'm wrong?