OK, need some additional information first:
1. What exact Mac model do you have?
2. What exact version of Snow Leopard are you running? Here is a link to the last Combo Update issued by Apple:
https://support.apple.com/kb/dl1399?locale=en_US
3. Have you ever done any disk cleanup/maintenance/repairs, from a software perspective? For disk cleanup, you can actually do a lot of it on your own. Also, for such activities, it needs to be performed frequently. Obviously, Disk Warrior is an excellent tool for that, but besides your own efforts and Disk Warrior, an excellent free program is Onyx (
https://www.titanium-software.fr/en/onyx.html). Note that if you get it, you must obtain the appropriate version for the OS you are using. Myself besides frequent disk cleanup on my own, I use Onyx and Tech Tool Pro (almost as good as Disk Warrior) to keep my Macs "lean, mean, and clean".
4. This is
critical: are you making backups to an external device?
Using your own efforts, Onyx, and Disk Warrior would most likely help in your case, but if you do not have backups, it will be risky with Disk Warrior.