I know that sometimes you can feel sad because of what happened but please know that those feelings of sadness, anger and confusion will soon disappear and turn into happiness.
It's okay to be different, it's actually what will make people like you. Don't feel left out or boring if you don't do what everyone else is doing, you will be thankful soon that you didn't partake in their "fun".
Sometimes you need to break friendships as they are bad for you. It may be hard as you have invested so much time, money and energy into them, however it is for the best and you will find friends that will help you grow rather than hold you back.
Even though people have hurt you don't hold grudges it will take up too much of your time. Instead learn to forgive and forget and you will be happier.
Don't let anyone tell you that you dreams are too big and that your dreams are unachievable because no dream is too big and trust me when I say you will achieve anything you put your mind to.
And lastly, You know yourself extremely well. You know what you like and what you dislike so be more confident with your decisions.
Love 18 year old you x