Hello,
That's what I do on daily basis: I clean and *secure* compromised websites.
Yes, you've been hacked, but it should not be hard to recover.
Additionally, you have to upgrade Joomla - your current version (3.3) has wide known vulnerabilities. I'll do it for you if you wish. I'll also send reconsideration report to google and I'll help you to remove spammy URL from google index (only google may remove it, but we can prepare proper redirections in .htaccess, send sitemaps etc.)
Please take a look at my profile (feedbacks):
https://www.freelancer.com/u/adamlachut.html
Unfortunately, I could start 27th December.
Ok, just let me know if you have any questions :)
Kind regards,
Adam