Sitting on the couch and it is so low, what can I do to fix that?
Purchase or make furniture risers to place under the legs of the sofa.
Different furniture risers.
How about installing furniture legs on it. There are so many options. Try googling, "furniture legs for sofa." Check your local hardware store too.
Could you make a base out of pallets, adding stained or painted boards across the front and sides of the pallets to create a solid appearance? I haven't worked with pallets, but from the pictures I've seen, it looks like this idea would work.
If you have cusions instead of a solid "seat", put foam under them to raise them. I found a 4' piece of foam at Walmart to put under the cushions on my rattan furniture to cover the wooden "spacers" under the cushions, which I invariably sat on when I sat down. Ouch!