I realize that you are not I. In fact, I wish I'd had your clear view of things when I was in approximately the position you're in now. One of the big differences was that my parents were much more controlling than yours are, and I never made a decision for myself until I decided to get married after finishing one year of college. Of course, my parents said no, I did not have permission to get married, period, end of story.
What we did was get married anyway. It didn't take 6 months for me to realize that as much as I liked being out from under the parental thumbs, I really didn't want to be married. I wanted to be back in school and working toward a degree. However, by then I was pregnant. Long story short, I eventually got the BS degree at age 25 and the MA at age 30, `while raising kids, working, and trying--and failing--to have a good marriage.
If I were to give you advice, it would be this:
1. Move out and get an apartment while you are working on the master's degree. Most schools have fellowships or teaching assistant jobs that would cover the cost of rent & utilities. You will get to experience freedom and responsibility without also having to adjust to marriage at the same time.
2. Start planning the wedding. In fact, get your mother busy planning the wedding. Set the date for right after you expect to earn the master's degree and target everything to that date. You'd be astounded how much lead time one needs for a wedding to be sure you get the church you want, the minister you want, the caterers you want, the wedding cake you want, the photographer you want, the reception hall you want, the limo service you want, the dress you want, and the bridesmaids you want on the date you want.
3. Decide together if you want the emotional baggage of starting a sexual relationship without the benefit of clergy. Some people your age are able to separate sex from the rest of the relationship, some are not. If you are not having sex now, you have no IDEA what the differences will be in your relationship once you do start having sex. There is absolutely no way to be sure no pregnancy occurs except abstinence, however--people get pregnant every day while using two or more methods of birth control. A friend of mine was shocked to learn that she was pregnant even though her husband had a vasectomy (after the baby came, they BOTH had contraceptive surgery).
4. Check in frequently with your parents so they know they have not "lost" you. If your mom is helping with the wedding plans, she will have a lot of research to talk to your about and a lot of decisions that will require that you two confer. Eat dinner with them at least once a week and keep them posted on what's going on in your life. You will feel more "separated" than if you live at home and they will feel more "connected" than if you move closer to your fiance.