These guys posting are older and wiser than I am, and probably giving some solid advice. But to answer your question assuming you do get married and do come to A-school, your quality of life will be a little better than your single shipmates.
A lot of it depends on you personally as well, if you struggle through the program you will only be at home to sleep on weekdays, and on the weekends. A school was the hardest part of the pipeline for me, and I'm currently about 2 weeks from qualifying in prototype. If you already have good study habits going in, and you catch on to the material quickly, you will have a much easier time and you can have a solid 4 hours at home after work. If you're married, you and your spouse will live outside of the barracks, and depending on what sort of deal you can find, and if your spouse works, you can be making a significant amount more than your peers.
All in all, I wouldn't recommend getting married just because you're going in to the military, as all these much wiser people have told you. If you do get married, your quality of life will be a little higher at first, but you will not be able to prioritize your home life over work.