Housing issue

Right now my college is going through picking housing for next year despite it being only February. Me and my friend planned on living together next year in a house. Well when the deadline to planning was announced, I encouraged us to look for people to live with. She didn’t want to look and kept telling me we had time. I tried looking at back up plans but prioritized living with her because that was the plan. I had offers to live with people, but did not accept them because she continued to say we had time and that she wanted to live together. She expressed that she was very overwhelmed by the process. So I decided to help find housing for both of us to live together to alleviate the stress. Well I text her to let her know I found a house and that they wanted to know her answer. She then proceeds to text me that she already found a place that she accepted to live in without me. She found out the previous day and chose not to tell me. When I expressed how frustrated I was because the plan was to live together and I didn’t do certain things to make sure we could live together. She said that she was “sorry for the confusion”. I prioritized living together and she was upfront with me. Furthermore, she has yet to apologize despite the fact that I supposed to be her best friend. My housing plans have now been thrown into chaos and I might not have people to live with next year. I’m not upset about the fact that we aren’t living together, it’s the fact that she wasn’t upfront with me and used me. I don’t know if I should let this go or if I should end the friendship.