I've no idea where you're going wrong with Tinypic but this service is easier anyway:
http://www.hostingpics.net/
Click the first 'Browse' button.
Navigate to the location of your file and double-click on it.
Click 'Envoyer'.
When you see a thumbnail of your image, click on it. That will produce a full-size pic but accompanied by the HostingPics banner. Again click on the image, which will then result in a web page showing nothing but your picture.
Copy the URL of that page and post it here (or wherever else you need to).
Easy peasy!