Why Does it feel like this? Pls help!

It's been about an year I'm feeling this...like I'm not living in reality and I'm just in some simulation and leading life as its scripted by someone or in other words controlled by another person. As a result I'm not able to concentrate properly. And feeling so depressed about the time running. Exams coming this dec and I'm just anxious and stressful coz I'm not able to concentrate properly. And I'm getting this strange feeling of time running too fast. I'm not able to keep a track on time. Last week I was on a trip and it was really great,I know it's just been a week since that trip but I'm memorizing it as had happened some 10 years back.and feeling nostalgic or some form of sadness thinking about it.This cndtion is now causing me to forget Imp things like my life goals mainly and I feel like I'm in a game (like living for the sake of it)and at some moment I get this stress feelings and become desp thinking about my own life and where it's headed. there's more things to say.pls help