It probably won't have much effect, but I just felt like saying this to everyone here.
Life is tough at times. Some of us may be going through hell right now. But keep in mind that most of us are through most of it. Once we have grown up and moved out, we can become anything we want to be. Each of us will be able to live out whatever romantic fantasy we might have; we will meet others like ourselves and won't feel alone; we won't have to suffer association to intolerant bigots in our family.
And keep in mind that things could be much worse. Be grateful for what you do have and remember the good times in your life.
We all feel sad from time to time. Feeling blue is just a matter of learning to get used to a new situation - you are too young to feel sad for the rest of your lives just because someone dies, or find out your parents don't love you, or something else tragic occurs. You are sad because something has made you question your dreams. But once you set things back in focus and dream again, you will be back on track. I've heard it said that it is hope that keeps everyone going from one day to the next, and I have to agree.
It is just a matter of holding on to your dreams. They might be all you have at the moment, but they are enough.