If you could write a note to your younger self, what would you say in only three words?
I had two thoughts. 1) Words can hurt. 2) Try your best.
What would your note say? 
you are not as bad as you think. If you think no one will likes or loves you, thats unbelievable. You are joyful and fun, if you walk in your own shoes. stop trying to be somebody else. You are pretty just the way you are. <3
Avoid that girl and choose to finish your thesis on your own.
If you're already in it, woman up and request to transfer schools.
if that didnt happen...well...there's always therapy.
Believe in yourself, be strong, don't be scared. Don't let anyone to destroy your dreams, follow them. Don't trust people not even your parents uwu, be strong to move on... Don't be scared of love. I trust you, you can do anything you want... Please don't forget it.
You're going to go through some shit times but I promise you it gets better, just never ever put someone else above yourself.
Be happy
You matter
Don't smoke anything. Ever.
Don't be so oblivious; everything is not what it seems.
Don't drop out. Don't let them win.
Change for nobody.