Is AUTHOR wrong in the post ? POST : Hey there reddit, first time user, long time lurker, mobile user, etc, etc 
This will be a long one.

First let me give some background on me. I’m a 20 year old male, first year university student studying computer science A struggling one at that, however with exams coming up shortly and my less than impressive grades I’m getting already I decided to really take my studies really seriously over the winter break to try and push my grades back up to what they should be. 

My gf that I have been seeing for 11 months has been living in my parents house with me since last summer,originally it went from staying the night tho eventually being there everyday and I didn’t have a problem with it as for the most part. However my parents and my brother did and around two months ago a huge argument was started about rent pay and general living expenses ( I pay my share of the rent) it eventually led to my gf saying she was going to start spending more time at home. 
My gf had the idea that it would be great if i tagged along with her and moved out to her house to live with her and her mom instead and for months started to list off very logical reason why it would be a better choice for me, she spoke about it to my mom and convinced her that it would be a great idea too and while I said It did have some benefits and I would think about it, i was never really convinced. I used to share a room with my brother until my sister moved out and only recently I got my own room to do with as I pleased. 
With my mom on board with the decision and my gf going on about it every week and redecorating her room it felt like I was being pushed into it and it drove me away from the idea more then anything and just gave me mental stress.
Today on the phone she brought it up again and I just went silent, she asked me if I wanted to move out and I said not really, I want to have some of my own space for studying and doing what I want to do, she tried to explain to me that I could do all of that at hers but I just said it isn’t the same. She got mad and said she isn’t coming to see me tonight, that I wasn’t man enough to tell her from the start and put down the phone.
I’ve always wanted to move out but I want to move out on my own terms, I feel like right now it just isn’t the best time for me to do something like that now when I’m already stressed about university exams coming soon and such.

Am I being the asshole here or are my reasons justified?