Withdrawal problems

To start off with: I realize that I am not that old and that most of y'all would probably write this off as if I were some kind of child but please if there is anyone out there who is willing to actually listen to me I would be very grateful.
So to start off with, I am 13 years old (14 on Saturday). However, I consider myself to have a more "adult" personality (and sense of humor). Over the past summer, I started getting these feelings of loneliness, which I originally just thought it was because of puberty. However, over the past few months, the loneliness has been increasing at a rapid rate, as my friends are all getting into relationships and my family members are starting relationships/getting married. There have been a couple of times that I have felt so alone that I was depressed about it, crying for days on end and not wanting to go anywhere. I'm just curious as to whether those feelings are normal and/or how you have coped with them in the past. Thank you