I feel truly alone
I'm saddened to hear that, but what makes you think you're alone?
I have nobody to count on
You need to seek out a counselor and discuss your feelings of being alone. Go to a church group and try to make some friends and find people that you have something in common with.
Why are you taking this so seriously?
I do not think that you should make light of the matter and get serious help and attention needed for your depression and feeling alone. I can't stress how important of you to do this so it is necessary that you be more mindful of what you're feeling and just be honest about it and get help.