it's not hopeless
You can be happy, you may not be happy every day or all day and you need to remember that when your sad, it passes. I have in the past been clinically depressed and have seen my mom and dad go through this too. I couldn't believe it when it happened to me. Even when you feel like there's no hope for you and that you're useless, remember this happens to almost everyone at some point and to different degrees in their lives, people pretend things are wonderful and it's only those of us who are sensitive who let it overwhelm us.
I know how it feels to cry everyday and have terrible thoughts that you are not in control of, I also know how it feels to get past this. I looked for books, went for therapy, took medication, I felt so abnormal.
Here's how I feel better, I know I'm hypersensitive to becoming depression this means I have to be careful about what I do. I don't drink to much coffee, I take a B complex (this works), I took Omega 3 but found I was allergic to fish, if you can take fish supplements, this works great.
Most important of all, if you have to take medication to get passed the crying fits, do it. It helps when you find the right one, once you can cope again, take care of yourself in terms of taking your B complex and eating right, excercising never hurts and neither does praying.
I promised myself that if I ever got better, I would pass along the message that there's hope and all of your sad thoughts and feelings of despair will leave, you just have to keep searching for what works to balance out your body again.
Your stories make me sad because I remember how it feels to be that sad and wish that you find the strength to look forward to better days.