Virtually complete disapearance of past emotion and interests?

Sorry, I know this is really long but please I truly would appreciate it if you give it a read! Thanks in advance!

So, I am currently in first year university. Since roughly around the end of high school last summer, I have noticed that I have become extremely apathetic, and feel virtually no emotion or passion in my life. I just don't care about anything much at all. I have little motivation to do anything (although I have still maintained my high grades), and nothing seems to interest me the way it should. It feels like my emotions are turned down to a fraction of what they should be- I still feel emotion, but only as a faint shadow of what I used to. And now I've been without substantial emotion long enough that it is hard to remember what it normally feels like. And of course, since I don't care, I know I should be trying to change this, but I don't care enough to actually do something about it, which is why I have let this go on so long.

And yet I used to be so different. By the end of grade 12 I was a well-rounded achiever (I paid for first year entirely on scholarships) and was passionate about all my different activities in several different areas. I was also highly motivated, but more importantly I was really REALLY looking forwards to everything: exploring the world around me (which was about to open up completely after high school) and learn new things (for example, how to speak French, dance salsa, sing, drive a car with standard transmission, among others). I felt like the world was mine to embrace and there was just so much out there waiting for me to discover, I was eager to do so as soon as I could. Despite never being particularly emotional, I felt emotion significantly stronger than I do now.

For the past months, I’ve just been going through the motions in life. It’s not that my life is bad, (objectively, it actually looks good) but it means nothing as I don’t care about anything including the stuff I used to care about. At university I'm surrounded by everything I’d looked forwards to for years, but right now, it is wasted on me as I just don’t care (although somewhat ironically this isn’t causing me any emotional pain due to my detachment!)

I need to figure out why I changed like this, and what (if anything) I can do to try to restore my previous mindset. Does anyone have any suggestions? Or have you experienced a similar phenomenon? Anything constructive would be appreciated! Thanks!

So , the fact is that you need doctor .