Time seems to be going by so quickly. Have you ever thought "I will never get this done by its deadline!" or "I wish I could have more time to finish this" ??
Everybody feels this! You are not the only "lazy" or "not super productive" one.
FIRST, stop calling yourself these things. These attributes can come from you comparing yourself with others. Instead, try to build and follow your own road at your own pace.
BUT, if you want to accomplish more during your day without having to cut back on your other activities - your hours of sleep, etc. -> HERE ARE SOME PRACTICAL and EASY TIPS to embrace for 2021:
Plan your day: Simple as 3 words but very powerful by the results! Time flies when you are occupied
Do efficient breaks: Breaks are important to stay efficient on the long term
Practice continuous learning: What a nightmare to have to feed your brain with an entire semester the night before the big exam! Continous learning helps also to keep the information on your memory much longer
Discover and exploit your own study style: get to know which methodology works for you to learn faster