Scan them and start rebuilding with an editing tool.
There is no easy or fast solution.
Your thread title refers to preserving the film and your message refers to restoring it. The only way to restore the images is to digitize them and improve them digitally. The only way to prevent the film itself from deteriorating more is to keep it in acid-free (archival) containers stored in a cool, dry, dark place. In your part of the world, you might have to use air conditioning to keep the air dry. Perhaps others know of effective desiccants that could be used in lieu of air conditioning.
Consider outsourcing the scanning. If you decide to photograph the photos, there is special equipment that can be used to optimize results but I'm not at all up to date on what the equipment might be or how expensive it is.
Clarifying whether the film is positive, negative or a mix of both will surely help people provide more helpful responses.
I agree with Mike about finding someone who can do high quality scanning. I don't have to deal with heat and humidity but a few years ago had some 40-50 year old B&W negatives scanned and turned into positives. I was then able to edit the images; I happen to use Photoshop. The whole process worked well.
I suspect that your camera will not be ideal for copy work, but setting up a copy stand with even light sources on either side is a LOT faster than using a flatbed scanner. The other advantages is that flatbeds are notorious for having dust and other dirt particles on the glass, meaning that you have to retouch those issues out of every image as well.
If I were doing it, I would not use a flatbed scanner for sure. But given your equipment, it might be the only reasonable option.