Busy couple

My boyfriend is currently working 3 part time jobs while going to school full time to finish his bachelors. I’m also a full time student working 1 part-time job and doing a lot of pre-med extracurricular like research and hospital volunteering. We’re just both so busy and I feel like we’re slipping away from each other. Sometimes we go days without talking and when we do it very brief. Any advice on how to maintain the relationship?