A., as the mother to a blended family of seven (his, hers and those born of others), I can tell you from first hand experience that what you are going through is hard on everyone, but your boyfriend is absolutely right in not wanting your daughter in the bedroom at night. Whether or not she is allowed in your room other times has to be a joint decision based on your lifestyle and what you want for your future.
My children were used to sleeping with me until I married my husband. He was very adament that they sleep in their own rooms and while he didn't say so at the time, that they not come into our room at all. I believe it is a very normal desire of the man to protect what is, in a lot of cases, his only territory. (Read Men are from Mars Women are from Venus for a better understanding of this) When my children first began sleeping in their rooms, I spent a lot of time going to them after knocks on the door in the middle of the night. My husband also went to them. They adjusted and were none the worse because of it. They still got the comfort they needed, learned to sleep in their own rooms and my new husband protected "his" domain at the same time.
That being said, my children spend a lot of time with me in the bedroom during the day even now. While my husband is at work, my now teenage and pre-teen children (as well as the dogs and cats) can all be found in the bedroom watching TV, on the computer, playing games or simply talking. My husband doesn't particularly care for it, but also understands that this is how and where I spend some of my favorite time with the kids.
Oh and as a side note, when my pre-teen wakes in the middle of the night which she does sometimes even to this day, it's usually one of her brothers (or her older sister when she's here) who get up with her.
You have my best wishes for this and if you need to talk more, feel free to send a note.