The plan above is a general structure, it is not the law. You don't have to follow it 100% to achieve results.
However, adhereing to a training schedule (and to the corrolaries, nutrition and rest) is generally the best way to improve your fitness in your desired discipline. These schedules are for those who don't have a personal coach or are not already following some sort of plan. If you are on a plan, it's best to stick to one plan at a time, and not try to mix and match. Consistency is key, and arguably more important than the specific stimulus of one workout set over another.
Most importantly, keep in mind that you are a college student, and the demands on your time, both academically and socially, are great. If you feel like you are constantly tired, pay attention to that. If you are feeling fatigued, try, if you can, to start the given workout for the day, and if you still aren't feeling it after 10-15 minutes of warmup, either spin easy for another 30 minutes and go get some food, or turn around and go back to bed. Training, racing, and school will keep you busy and make you fatigued, and some times it's ok, and even needed, to push through fatigue to break fitness plateaus. However, you can, quite quickly, push into a overtrained (or, chronically under-rested) state. As it often takes longer to get out of this state than it does to get into it, erring on the side of caution is generally encouraged. If you are concerned, but can't quite make up your mind, consult either myself or one of your peers as to what you should do. Having a sounding board can often help with making the right decision.
There are 3 general Macrocycles (year by year, season by season, and month by month), and 2 general Microcyles (week by week, intra-week blocks). These cycles are designed to systematically increase or decrease load/trainging stress.
Year by year - The largest macrocycle, this one generally takes at least two years of following the same plan to help with highlighting annual fitness patterns. Difficult to fully utilize with group training plans, as how one cycle will differ from the last is athelete dependent.
Season by season - Fairly straightfoward, this cycle is based around a build/peak/recover model for a particular season.
Month by month - This is the smallest of the large cycles, and usually follows a 3/1 pattern of 3 weeks increasing intensity and 1 week of recovery.
Week by week - Inside of the month, the first week will generally be the easiest, the second week will increase intensity, volume, or both, and the third week will generally be the hardest workload, with the fourth week being a recovery week.
Intra-week blocks - Weeks generally follow this pattern, with 2 recovery days and 2 micro-cycles. Monday - recovery, Tues/Weds/Thurs - cycle 1, Friday - recovery, Sat/Sun - cycle 2. The midweek block will generally be shortest time on bike with the highest intensity on Tuesday, longer on the bike with slightly less intensity on Weds, and your longest mid-week day with moderate intensity on Thursday, and the weekends will follow an abbreviated approach if not racing (Saturday, mid/high intensity, Sunday, mid/low intensity with longest time on bike).