I am only a third year in college, but I also worry about early burnout. One thing I am currently doing is building relationships with current elementary school teachers. I have conversations with them about how they balance their work and home lives. One of the biggest things they have told me is you have to set boundaries. Choose one or two days a week where you will stay longer or go to school earlier to get work done if needed. If you need to work on the weekend, choose Saturday or Sunday, but devote at least one day for a break. Another tip they have shared is after your first year or so, don't bring your work home, otherwise, you will always be tempted to do something. It is also important that you build a solid support system and an environment that is positive. As teachers we should be helping and encouraging one another. While talking with other teachers keep the conversations positive and mention the good things that are happening in your classroom and students' success. There is definitely a time and place to discuss classroom/school-wide problems, but don't let those things consume your conversations. Those conversations will leave you feeling down and unhappy. Lastly, make sure to always make yourself a priority, because if you aren't then you won't be the best you for your students.
Thanks for your question!