Need help on planning time to rest!

Since starting grad school last year, my priorities have shifted somewhat. (This is my first time back to the forum in who knows how long, so I apologize if the answer I'm looking for already exists here.) I'm swimming now to maintain form and speed, and just because it makes me so happy every morning. I'm not training for anything in particular, but if a meet comes up that fits my schedule, I might go. Over the winter break, I got both a TRX and a road bike with a trainer. I LOVE the TRX. I've been using the 12-week Force program, and in the first four weeks, I've already seen and felt a difference. Riding the bike on the trainer is also kind of fun, but only if I imagine all the places I'll be able to go when the weather gets warmer. Here's the thing. As the month is coming to a close and I'm back in school, I'm TIRED. The gains I've made on the TRX are plateauing and I'm starting to feel creaky in some joints, especially my knees. It's time for a break. However, I need a planned break, not just a week on the couch. Anyone have a good idea of how I can structure a productive break for the kind of person who likes schedules and training plans? FYI - I'm a 36 year old woman who swims an average of 3,000 yards in an hour long workout, and I used to be able to comfortably do 100's on 1:30, but these days it's more like 1:40. I didn't compete at all when I was younger, or do anything more athletic than marching band. Thanks for any advice you have!