Hello, I have hot water, but no cold water in any faucet. My pipes did freeze over winter, but I thawed them, and up to yesterday cold water worked, it is now warm out. I went into crawl space, and could feel water running through main water line when the hot water was turned on, but I could not feel water running through main water line when we turned cold water on? What could be the cause?

You obviously have cold water flow IN or you wouldn't have hot. So, the blockage has to be somewhere after the hot water heater. Could be another valve that shut itself off, a gate valve perhaps, they have been known to deteriorate and drop the disc. Follow the line after the HW heater and see what you find. Clogged filter?