I keep having this feeling that I'm just doing the wrong thing with my life. I'm not sure if this is normal and just me going through the motions, getting used to a completely different lifestyle.
Yes, it's normal. You haven't given details about your background, so just as a general concept, the further your past experience has been from the graduate-student-being-socialized-into academia way of life, the more challenging it is to make the change.
Think about new military recruits, who may be used to sleeping late and playing video games for hours every day, having someone make whatever dinner they ask for, and being "off the clock" when work time is over. Suddenly, they have to learn a whole new life: saluting, marching, hiking in full gear, arising at an hour when they might previously have just been stumbling home from the Club, eating whatever the mess folks slap on their trays. And it never stops, it goes on 24/7. You also are learning a new social structure, a new career, new language, new ways of evaluating your skills and progress, and (I'm guessing, without knowing your age) also perhaps making a transition from early to mid-twenties -- becoming fully adult.
As has been said in a similar context, decide whether you are running
toward something or
away from something.
Other have given you excellent advice. You're doing very well in your program; there is no benefit to you in quitting at this point. Please try to complete at least a full year, and, if at all possible, a master's degree. However, that doesn't mean you can't keep thinking about whether the PhD is what you want. Spend some time thinking about what your alternative would be. When you have a couple of careers firmly in mind, set about finding out about them the way you would research a topic for a paper. Read articles and/or books, identify people to talk with about the work, possibly get a summer job either doing the work or being in the environment where it's being done. If you decide that's what you want, then look at the steps you need to take to get there. Also, there may be a career development office at your university that can supply information and perhaps some testing to help you identify an alternative career.
Best wishes for the new year!