I've been there and done that when I was in middle school (yes, that's a little sad). For me school and having friends was very up and down, given my situation I started out shy when I first started school, started coming out of my shell in 2nd-3rd grade, then puberty struck for me after 6th grade and with that I gained so much weight in one summer that I legitimately looked like I was in early pregnancy even though I wasn't overweight. Let me add, during that summer I ate the same as far as I can remember, usually it was not unhealthy either.
Most of the 12-13 year olds of 7th grade back then would make fun of me because of that, it totally crushed me mentally and destroyed just about all of the confidence that I had gained. In hindsight looking back at those years, I should have tried to get my dad to get me out of those classes and back with the group I was with in 6th grade. For my area, we did switch rooms in middle school, but stayed with the same people the whole time. 6th grade was a lot of fun for me because I got switched out of that group I'm talking about, but 7th and 8th were completely awful.
High school was better, because most of the people I'm mentioning went to a different school, but because of those two middle school years, I was shaky socially because I was so worried that people would make fun of me. It wasn't that I didn't have friends, though. It was only once I got to my senior year of high school where I started to make a turnaround. I stopped caring about what others think, and for me, fall 2012 through my first year of college was a lot of fun. But in a way different perspective than most. I was friendly with some at college, but I really enjoyed the freedom, and being able to go hike out in the country.
I sometimes wish that I can delete the 7th-8th grade period from my life.