Having been in the situation for a few semesters after coming back from a really yeshivish-type bais yaakov seminary, I really feel for you.
You will be in for many challenges. One of the most important things I did for myself was set gedarim with a Rebbetzin that I felt understood the situation. She would ask me on a fairly regular basis if I felt I was still holding by my gedarim.
Some of these gedarim were to stay out of social areas like cafeterias and common rooms (even Hillel common rooms!). If I needed to eat or take a break, I went into the cafeteria to buy food and ate it in the areas in the library where one is able to eat… Or I ate it outside on campus… I spent an awful lot of time with headphones in my ears even if there was no music on… People get the impression that you do not wish to socialize when you have a cell phone on, bluetooth on, headphones on, or a book opened… or any combination of them…
Find yourself a Rav who knows a lot about college courses and college situations so that you know you have someone to ask before the questions come up. It is very stressful to be in a situation without someone to ask.
Let me know if I can help you with anything…