It was like semen, only not as thick. I'm worried now – am I sterile? Do I have a low sperm count? Will I continue to ejaculate like this?
You probably have nothing to worry about. Semen changes consistency from time to time. And remember, it takes only one sperm cell to fertilize an egg, so it's rare for a male to be completely sterile. You can always have your sperm count checked at a fertility clinic, but for now I wouldn't worry about it.