You're always saying that you want to be married and pregnant by the time you take on clients, but have you really ever stopped to think of what happens if that DOES NOT happen for you? 2 years isn't a long time at all to meet someone, date, get engaged, and then married. Very few of my friends that ended up happy dated less than 2 years. I've known my boyfriend for almost 6 years, but we didn't date initially. It took 3 years for us to finally date, and that was after I stopped looking. I'm worried that with your shear desperation for someone, you're either going to be left alone in the dark or with someone who is horrible.
You need to take some time to write out the pros of being single in 2 years... because you have to realize it is a very real possibility. You have to prepare yourself for that and you have to find a way to be happy about that.
For example, I will be moving every 2-3 years after I graduate (at age 29) from my PhD program. A huge pro for me would be that I would be unattached and free to move as needed without having to worry about a significant other finding a job or finding a school for children. My likelihood of accruing extra debt is lower, and I'm a lot more free to be able to go out wherever and with whomever I want on a Friday night... or I can immerse myself in my lab work without worrying about someone being angry with me for being an hour late to come home.
If you only ever look at the cons, you're never going to be happy in any situation, even with your grad degree. Yes, you learn a lot about yourself in graduate school, but it is not a place to find your whole self. I really think that you need to spend some time working on yourself before you spend a ton of money on a grad degree when you might find yourself mentally unable to handle the situations that will be presented to you on the job. These people that you're going to be working with need someone who will not judge them, who they can depend on to find ways to appropriately assist. How can someone who doesn't know themselves and only views one way of life as giving happiness provide that? The way you talk, if a girl like your friend came in, pregnant, scared, and not knowing what to do, you wouldn't be able to help them. This can be incredibly damaging to that person... and I know that I wouldn't be willing to even practice if I didn't have myself sorted out to the point where I could respect that lives of others do not have to fit this idea of "perfection" that you have in your mind.
To answer your initial post: I have been on my own since my MS, and moved 13 hours away for my PhD. Sometimes I am a little lonely, but I call a friend at home or we play games over IM, or I Skype my boyfriend. I spend most of my time at school (10-12 hours per day) and the rest of my day studying and reading papers. Some weekends, if I have time, I go shopping with some others from my program. Right now, we're prepping a welcome party for one of the guy's wives, so I get to shop for a party when I get back. Any time I am at school, I'm extremely happy. You just have to put on your big girl pants and go for it, be it single and happy, or married and happy. There's no other way to be.... because there are good things in nearly all situations.