Unfortunately, the only online therapy I've ever come across whilst researching has required a fee of some sort. I had a long look on Google just now for you, but everything I'm looking at asks for money before any online conversations can start. You could always continue looking, but I'm pretty sure it's going to be difficult to find a free online therapist. There are always all types of forums that you could go to to vent your feelings and seek advice, or you could always email the Samaritans here: jo@samaritans.org
How long does it take to reply to an email? Emails are always answered by real human volunteers, there are no "automatic" responses. If you email we try our hardest to get back to you within 24 hours. If you need immediate support you can pick up the telephone at any point and speak to a Samaritans volunteer. You can phone 08457 90 90 90 if you are in the UK and 1850 60 90 90 if you are in the Republic of Ireland.
How does the email service work?
Trained Samaritans volunteers provide the same kind of confidential emotional support to people in distress as on the telephone. Emails enter a virtual queue, and are picked up on a rotational basis by a Samaritans volunteer based at one of our branches. No automated responses are used.
Is the email service confidential?
The software that supports Samaritans email service is specially written to be completely confidential and reliable. The software works by removing the sender's details, such as email address, from incoming emails before they are seen by Samaritans volunteers.
Emails are kept on a central server for 30 days so that if you want to email us again, we can see that you have contacted us before. After 30 days, all emails are automatically deleted and no record remains of the emails or the contents.

Taken from here: http://www.samaritans.org/talk_to_someone/email.aspx
This is quite different from therapy though, it's just having someone there to listen and offer advice or understand as best they can.
Other than that, I'm afraid your other options include actually voicing your hurt. I know telling someone can be the scariest thing in the world to do, but after the first few moments, it's not so scary anymore. And it can get you help, it can help make things better. If you find it too difficult to just come out and say that you're hurting and are feeling depressed, you could also try writing things down in a letter and giving it to a parent or teacher or whoever.
It's really not easy, is it? I'm really sorry. I wish it were easier for you to get help and get on the road to feeling better and coming through this depression, but sometimes we just HAVE to take control and make that decision to speak out, despite how utterly terrifying and difficult it can be. I know it's scary, but once those words have been spoken, that's it. You've done it. Just a few moments of unpleasantness and awkwardness, and then you've voiced it and it'll be out. And, hopefully, you'll be getting help, y'know?
Best of luck to you. Really. If you ever need anything at all then feel free to PM me anytime. Good luck, and I do hope you find the help you need and want to get through this.
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shelves in the closet? happy thought indeed!