I [23M] currently live with my girlfriend [24F] and I don't know if I want to date anymore

So my girlfriend and I have been dating for four years and I am just fed up. She recently brought home a senior dog (we already have 2) and decided to keep it without talking to me about it what so ever. We live in a very small one bedroom apt. I didnt even want two, but it has always been a dream of hers so I was ok with it. Taking on another animal is a big responsibility and I am hurt because she didn't even take my feelings into account when bringing it home.

She also talks about wanting to move specifically to California regularly, we live in Michigan. She isn't close to her family at all so this is no big deal for her. I like the idea of moving in the future, but am extremely close to my family and don't know when or where I would like to move. I feel a lot of pressure from her in this regard as it seems that she won't be happy unless she moves.

She has a hard time finding happiness at work because anything she does she ends up loathing after a few weeks. She brings this negativity home with her which bothers me a lot as I am generally a very happy and positive person. I find that we mostly talk about negative things in her life instead of focusing on fun and positivity despite my attempts to.

As of late I keep getting the feeling that we have just grown into different people as we don't really have any hobbies that we enjoy doing together anymore. Whenever I suggest we do something that I enjoy she groans and agrees, but I know that she isn't really enjoying doing these things.

We currently have our lease until October and I have brought these issues up to her multiple times. I don't like coming home to a negative place that is full of animals. I feel that she is being extremely selfish and inconsiderate of how her actions make me feel.

I feel that this is over and I don't know how to end things. Any advice? Am I jumping The gun? We have a lot of fun together because we can goof around and make eachother laugh. The things we do do together we enjoy. I just don't like the selfish things I have been seeing over the past 6 months or so.(since we moved in together)

tl;dr: been dating 4 years. Get along great, but girlfriend has been making very selfish decisions since we have moved in together and is not taking how I feel into consideration. Our lease is until October. Should I end things? If so how?

Thanks for the responses in advance