My answer: Courage! There are normal ebbs and flows to any long project, so expect yourself to flag at this point. Four years is a lot of investment and you are relatively close to the end. The economy is bad, you won’t find a job right away anyway (I’m kidding here, but...), so stick it out!
You might do a few things. First, you might ask your boyfriend and family specifically to encourage you more. Tell them what you need — a regular call, care packages, to be asked about your work, or something else. Tell them you are discouraged and need their help and be specific about what you ask for. By asking, you might find that the problem is miscommunication. They may actually be trying to support you by not putting any pressure on you. What they say is something some PhD students need to hear: “You are not your project. We will still love you if you quit.” Or they may have no way to relate. They may not understand why this is important to you and think, if you are expressing that you don’t like it, why you are still doing it? Your boyfriend may even resent your studies if they keep you from time with him. So find out what the problem is first.
If you think your boyfriend and family are not going to encourage you, find a small group to do so. This can be students in your lab, classmates, or it might be another type of group. When I was in my PhD, I was in a dissertator support group hosted by the grad school. Every week we met to tell what we had done the week before and what our goals were for the coming week. It was extremely helpful. The counseling center may offer such a group on your campus. Finally, have a prayer group. In my master’s program, I was in a group of five academic women that met every week for prayer. Now in my career, I am in a similar group. A group like that can relieve your loved ones from meeting needs they really cannot fill.
It sounds like you are discouraged but unless you really want to quit, don’t quit just because you are down. There are ways to get your needs met, and what you are experiencing is very normal.
When it has come to major decisions, I have “just known” with a gut-level knowledge what I should be doing, which grad school to choose, when to get married, and to whom. That doesn’t always mean I want to be doing what I know I should be doing. For example, getting married wasn’t really on my mind when God called me into that life-changing process — a huge lesson in trust for me. I had a problem almost opposite to the one you describe. As I worked away in the last years of my PhD program, I was so certain that I wanted to finish despite an extremely dysfunctional relationship with my advisor that I needed to constantly turn the decision back over to God.
My advice is to take some dedicated time to do some soul searching and praying. Take a retreat. Or if you find it necessary to take more time, take a leave of absence from grad school. I know it feels like the clock is ticking on your degree, but taking the time to be certain about your decision to finish could be so motivating that in the end it will save you time. If there is something specific that you consider doing instead of pursuing this degree, then find out more about the “greener grass” on the other side of the fence. I recommend seeing a career counselor. Your school likely has several of them. Or, you might go to a private counselor specializing in career counseling. These individuals love to research career options, so let them do it for you.
Now if you do decide to continue, I agree that you must find a community that will support you. Your family and boyfriend likely don’t want to put the extra pressure of expectations on you, but it is hard to finish when you are not certain of your vocational calling. I suggest looking for at least two other women who are either in the last years of grad school or who have recently finished. If your school has an InterVarsity chapter, that is a great place to start looking for support. Try to spend at least half an hour a week talking with these women and praying through each step of the research. Be vulnerable with each other. It will do you no good to gloss over the major hurdles. Talk it out. Help each other set goals and hold each other accountable. I found that the time I spent in these discussions and in prayer over the issues gave me the energy to keep working. It was definitely not precious time wasted.
As generic advice, I would suggest “Pray!” Ask God to show you where your uniquely-given passions lie. I will pray with you.
Have you considered the possibility that the current “neutral-supportive” attitude of friends and family is a blessing? (One wouldn’t want to get “encouraged” into completing a PhD when one’s passion is separate from the program. What would happen after graduation?) I am confident that prayer and discussion of “what makes you excited” with advisors, mentors, friends, and family will help you find your special niche. My suspicion is that when you find that niche, your friends and family will provide all the support you need.