I'm not sure that a big regex like that is entirely necessary - if you're just looking to get links, you could use a much simpler regex, like this:
/(https?:\/\/[\w\d\$-_\.\+!\*'\(\),\/#]+)/ig
According to RFC 1738, urls are only allowed to use the characters specified in the class above, so it should cover any valid url, without such a gigantic mess of a regex.
You can also use a tool like regexpal.com to validate regexes, which helps find issues. That said, I pasted your regex in there and it crashed chrome, so it may not be a great help for a beast like that :)