@Aya dh ,
NOTE: I am not a medical professional.
I'm guessing you're a teenager or young adult, and so a lot of sleeping is pretty normal.
You may also be crashing off a lot of caffeine use during the semester, and/or a lot of stress or activity.
It's also possible that you have a degree of seasonal affective disorder (just Google it), as these are the darkest days of the year. Getting outside more, and taking advantage of any bit of sunshine you can get, can help with this, as can getting a full-spectrum light.
Inactivity can tend to breed inactivity, so you need to take charge of things, even if it's briefly. Try to get out for errands if nothing else. And try to amp up the activity, even a little. Being active is not an all or nothing proposition. If, say, you would have driven to the post office, try walking instead. You'll get outside, you'll be in whatever sunlight you can get, and you'll get something accomplished, all at the same time.
If these feelings persist, and in particular if you give up the things you enjoy doing in favor of sleeping, then call your doctor, as this could be a sign of depression.