Idk if I'm depressed... Or if I'm being a baby

I have a great family who love me. Great family friends who value me because I'm the oldest kid in the friend group (I'm 21 soon). I have friends. But. I feel really lonely sometimes. And I don't know if I'm depressed or if I'm just being a goddamn baby and need to get over it. It's not like I'm not busy. I have so much shit to do all the time. But I procrastinate a lot and feel bad. Idk. Just a stream of consciousness on here. I feel guilty because I'm not studying properly for the MCAT. I'm scared about my future. And this kind of paralyzed me. And I cry a lot haha. ..