Roll on or paint on roof sealant for many small holes?

[fishnaked]

I washed my roof cover the other day and strung a line to hang dry it. While walking under this now tent-like structure, I looked up and was shocked at all the sunlight coming through the holes. Small holes. They appear to be cracks from folding. There's probably not 6 square inches that there isn't a hole!

I'm on a budget. This is a rustic backcountry yurt, i.e., it doesn't have to be perfect...though I don't want it to leak like a sieve in a downpour.

Is there a sealant of sorts I can paint on that will allow me to squeeze a bit more life out of this cover?