I’ve taken three semesters of Latin in the last two years of school. I know what you’re talking about, and it took me about a semester and a half before I started “thinking in Latin”, per sē. It’s en exciting moment when you realize, “Hey! I’m not translating this in my head any more!” It’s just something that happens as you really learn a language. Really immersing yourself in the language (taking a trip to Mexico; or, as a more affordable option, watching a movie with Spanish audio) would be a way to speed up that process.