It's completely manageable, you just have to schedule out what you're doing and don't deviate from it. Freshman year I did club swim and the coach told me to lift weights after since at the time i was very skinny (especially for a sprinter) and it helped me become faster almost immediately. The practices were tiring already so throwing in a weight workout after or before it was tip of the iceberg for me. so i stopped so my body could rest a bit. i was in really good shape and gained a bit of weight since i ate like a king EVERY meal.
~Eat a lot more for energy
~Follow a schedule (factor in sleep as well, it will hurt or help you)
~Learn to Multitask (study in between sets and while you're eating)
~Place goals that are achievable (weight gain, speed in distance, food diary[to look back on haha])
Hope this helps a little. I know that everyone isn't the same. I've always had a lot of expendable energy so I feel my body is always on a glucose high. so adjust to your lifestyle
good luck with all of this next semester.