In all of the Universities that I've attended, there are two options. You can have the less expensive dorms, where you share the showers with the "community" or you can go for the more expensive dorms and have a bathroom IN your dorm room.
However, in the community showers, there are curtains or doors and a wall dividing each individual shower. It won't be like a locker room, where all the dudes shower together and all the chicks shower together (most high schools don't have these anymore either lol).
ANOTHER thing you can do, is actually come out to the school. Most schools have LBGT communities, so there will be no hate coming to you, and if there is - they can get in some major ->-bleeped-<- for it. If you come out, and you have to use a community shower, then you may be able to shower in the area that you deem more comfortable, or other facilities may be available to you. Sometimes they can even give you a roommate in your preferred gender, or again - you can make another option and swing for a single. However, you said you didn't mind sharing with a male, so I doubt you'd opt for a single.
I think what you should do is look into it, and see if there are any dorms with a bathroom, and if there are, then you can see if the price is appropriate. If it is not, and it is out of the question, then I would suggest talking to your school about it and getting in touch with the LBGT community at the school to see what they suggest. There may also be some sort of co-ed bathroom as well. There are some campuses that have those.
I mean, if you pass pretty well, I would just sort of keep it hidden - and maybe let my school know. Merely wear a robe into and out of the shower(which you would do anyway lol) and bring everything you need in order to pass while under the robe as well.
I moved off campus last year(thank god), but I was in a single dorm, with a bathroom to myself. I was on the girls floor though. It was awkward, but most (except my RAs) assumed that I was just going to see my girlfriend or something.
I wish you luck <3