Oh, this is a good one! I really struggle with this because the end of the semester feels like a landslide. I don't have a firm solution, just a recommendation: celebrate Advent. At my house we light the candles of an Advent wreath each Sunday and eat dinner by candlelight. We play a lot of Advent music (no Christmas music until the week of Christmas itself) and generally try to think of everything before Christmas as a preparation for, rather than a celebration of, Christmas. We put up simple decorations and put them up slowly.
I have happy childhood memories of lighting candles with my family and listening to the story of the angel's visit to Mary. Now that I am a parent, I also feel my children's wonder and joy as they anticipate the coming of Christ. So I guess what I'm saying is that Advent reorients my sense of time from the end of the semester, with its anxious demands, and from the secular Christmas/commercial season, back to Christ's coming as the center. (If this appeals to you, you might check out the Advent Conspiracy site. There's also a lovely little series of books titled Let us Keep the Feast that will help you use the church calendar to strengthen you and your family’s walk with Christ.) Celebrating Advent doesn't fix those other problems, but it does put them in perspective.
The challenge of balancing work and family is tough all the time, but it gets even more complicated over the holidays. My first suggestion is to recognize that there will be more good things that you would love to do, or that people expect you to do, than you can actually do. Don't give up your ongoing self-care commitments like exercise or Weight Watchers or church small groups that help you to stay healthy and grounded. I could go to amazing musical concerts every night during the holiday season, but my prior commitments to my personal trainer, my book club, my peer supervision group, and my church bell choir mean that many nights are already committed. That's okay. It's a better choice for me to go to one or two events that fit my schedule than to try to do it all.
My second suggestion is to choose activities that are likely to deepen your relationship with Jesus and/or relationships with people you value. My church has quiet and moving Advent services on Wednesday nights in December. Those get a high priority for our family, because they facilitate us taking time out of our busy schedules to listen, to calm, to meditate on the coming of our Savior. We are invited to department holiday parties, a holiday party thrown by our accountant, concerts, other church activities, and those are lower down on the priority list. We might go if we can and if we're not too tired, but often we deliberately say no just to protect some time to be home.
Third, as a working mom, I think one of the most important things is creating rituals. My house will never be perfectly decorated, but driving to Swan Farm to choose our Christmas tree as a family is a must. Then we decorate the tree, and each person hangs his or her own special ornaments...which means that some ornaments wait in the living room until my son gets home from college! In my house, I'm not the baker — my husband has his Grandma's Christmas cookie recipe, and we love eating his creations. We go to our Christmas Eve candlelight service at church, and we have overnight Christmas egg casserole with red and green peppers and a Swiss nut torte for breakfast on Christmas morning. Rituals are what connect us to each other, and to our heritage. It's probably better to do a few things consistently every year that are meaningful to your family than to try to keep up with folks who make Thanksgiving and Christmas a full-time occupation every November and December.
I know families who make gifts to give to teachers and friends at church. I think that's a great idea if it really is a family activity, but not if it's a mom activity that she feels she has to do just to keep up with expectations, causing her to feel obligated to stay up late at night baking or dipping or stamping. I have no problem with buying cookies or other foods for school or church events where my child is required to contribute goodies. We aren't obligated to gift everyone in sight. If there are special people who we want to recognize and give a Christmas gift, like teachers, but we don't have time to make or choose special gifts for each one, there's nothing wrong with buying a block of gift cards at Costco, and spending our valuable time writing a thoughtful card to that person with a gift card tucked in, instead of driving to the mall and wrapping.
FInally, be honest if academic responsibilities make you unavailable at times that other people are in full Christmas mode. "I'm so sorry that I can't come to your open house; I'll be grading final exams that weekend and I'm on a strict deadline. Thank you so much for the invitation — I would love to catch up with you after the holidays when we can sit and have coffee without being rushed!" But don't be shy to say no without a reason, when the truth is that you know you'll be exhausted after the semester ends, and just need time at home. Especially for introverts, holiday events can be draining and require renewal time just to compensate for the energy required to go to parties. Listen to your heart and your body. Advent is a time to listen, to wait, and to reflect on the coming of Jesus. When in doubt, choose time with Him first.