Do thoughts really create our reality?

[AnthroHeart]

I focused intently on manifesting a desire, for like 30 mins. After this time I noticed my whole body was physically exhausted. I felt the energy about me thicken. I wonder if it's possible to feel a thought-form, if that's what I was doing. It was hard to keep the image still. It would sometimes move, and change. It's going to be hard to focus on a single thought that doesn't move. There's so much complexity to my desire, that it's hard to give it definition that is adequate.