Yes, freezing is a really good way to go.

Do I have to let the sauce cool after boiling before putting them in my plastic jars and freezing? Also how long will I have to consume the thawed sauce if the p.h is 3.5 and I refridgerate it?

How much it will have to cool depends on the containers you use. If you are using Ball freezer plastic containers or other brand made for home food freezing then it can be bottled up while still hot - bot boiling - but hot. Others type containers might not hold up to the heat. Test one first.

Once opened and stored in the fridge the shelf life will vary since it wasn't ever heat processed in the containers and the containers won't be sterile. You'll just have to watch for the development of off odor, molds, etc. Just a guess - but 3 months perhaps. I'd sure use small containers for it. ;)

Dave