I've been in 3 different inpatient units and I guess the one piece of advice I would give you is that, if you are serious about getting better, then give it your all - don't mess around - the only person who you will be cheating is yourself
Whilst I didn't want to go into a unit, when I was there it was fine - if anything it was a but of a relief to have all decisions made for me - I knew that if I didn't eat then there would be consequences ( a supplement drink or, if these were also refused then a tube was the next step). You will find things quite routine - breakfast, lunch, dinner & snacks will be at the same time every day and initially you may have your choice of meal options taken away (althought they do let you have a certain number of 'dislikes') but when you prove that you won't mess around and they trust you then you will get more freedom.
You might also find that you are quite closely monitored for the first few days - someone will stand outside the door when you're in the shower/go to the toilet but again that will stop when they trust you more
It is standard practice for them to search your bags when you arrive - and you won't be allowed any 'sharps' - so things like razors, scissors etc will probably be taken away initially
I would really recommend taking some home comforts with you - a favourite stuffed toy, your own duvet/pillow - things like that
If you have any other questions just shout
I was in a residential program in January. I struggled with anorexia with occasional bulimic tendencies and an exercise addiction as well. I'll tell you, as much as I was addicted to my eating disorder and loved the control, it was killing me and if I didn't go to residential I would not be here right now. I was scared to death when I went and pretty pissed off that I was forced to eat breakfast lunch and dinner but that's normal. A normal day consisted of getting up at 4 am for weights and vitals, than breakfast at 8, community meeting, groups, lunch, groups, snack, free time, dinner, groups, meds, and bed. There are smoke breaks and other medication times and snack times depending on certain needs. At first I hated it, but it really did help and put me in the right mindset. I was extremely uncomfortable with the changes in my body, and still am, but all of the girls there were feeling the same way so you will be able to connect. I've made some of the biggest supports and friends there. Although the problem does not just get magically cured once you get released, it teaches you how to cope and overcome obstacles in the real world. I still struggle, I'll admit it but it is better than being dead.