I'd ask how you're doing, but I pretty much already know. Middle school sucks, I know. The braces and the frizzy hair probably don't help all that much, but ride it out, it'll all get better with time. The acne will be gone in a few years too (for the most part), so don't worry too much about it all.
It seems like life pretty much sucks right now for you, and to be honest, it really does. Middle school isn't the end-all-be-all, trust me on that. The friends you have right now probably won't even be around in the next two years, let alone in the next six, but make sure you stick to the ones that will always have your back. When times get tough, they'll be the ones you'll want to lean on.
Go easy on Mom and Dad. Mom loves you, and only wants whats best for you and your brother. When everything else goes south, she will always have your back. You and her are going to butt heads over a lot of things in the next few years, but at the end of the day, she is almost always right.
The same rules apply for Dad. You and he won't argue as much as you and Mom probably will, but it doesn't mean he doesn't love you. He works ridiculously hard to give you the opportunities that you have, so appreciate them every day. Don't lie to Mom or Dad, because they'll know, and you'll get your butt kicked for it. They'll give you a lot of responsibilities over the next few years, but also a lot of freedom that you could never dream of. Don't abuse the trust they have in you, because you'll have a hell of a time earning it all back.
Appreciate everything that they do for you. One day, you'll realize just how special they are. Same goes with Yiayia and Papou. You haven't met Theo Pete yet, but he'll be coming around soon. Give Theo Pete and Papou a hug for me. You never appreciate exactly what you have until its gone.
Right now, it's only you and Alex in terms of siblings. He looks up to you, so be a role model for him. He's young now, so you and he don't really hang out too much, but that'll change with time. He'll mature, and so will you. He'll become your best friend, along with a new sibling that'll come along while you're in high school.
Don't worry, there won't be any babies coming along from Mom and Dad, but you'll get a new sibling nonetheless. Keep an eye out for her. From the first day you meet her, you'll know she's someone special. You, her, and Alex will get along just fine, I promise. You'll get in a bit of trouble with them every once in a while, but you'll always have each others' backs.
These next few years are gonna be tough, but you'll find where you belong.
Don't be afraid to try new things, and if something doesn't work out, it's not the end of the world.
Go out for the school musical, join the riding team, do something you never thought you could.
I promise that everything will work out exactly the way it should. You should go check out the firehouse down the road from you. You never know, you might just like it.
You'll be fine, I promise. Everything gets better with time. You'll learn and grow in more ways than you could ever imagine. Be patient. You'll love who you turn out to be.
(P.S. Dad will cave on the whole "no pets" thing, I promise. It might be when you least expect it, but I promise, he'll get there. Show them that you're responsible, and everything will work out just fine. Her name will be Pita, and she loves to cuddle.