You just have to think about all the terrible things in the world. Think you aren't good. Think that no one loves you.
But, because God loves you, he puts hundreds of Angels in your life. They're in your classes at school, to tell you how pretty you look, or laugh at your jokes. He puts them in the hallway to walk to your classes, to hug you, to ask you if you are alright. He has them text you. Words of love that you want to save to re-read over again.
He puts them at work. He give you nice friends to work with who will take out the trash so you don't have to.
He has random strangers compliment you by saying, "You are so cheerful with that beautiful smile of yours."
When that isn't enough, he has your yearbook get overwhelmingly full with words of encouragement, love, and beautiful things.
And finally, God gives you a patriarchal blessing. A small piece of paper saying, "You are wonderful. I know you can do this, and I know you will succeed. I love you, and want to help you every step of this journey. You mean more to me than you can possibly know. You will do hard things because you have the gospel of Jesus Christ to help you in your life."
And seriously, how could you still be discouraged after that??