Do you get cold water from your shower and bathroom sink?
I'm wondering if maybe your valve is broken in the kitchen faucet?
If you shut off the pump, and then take the cold water faucet handle off, and see if the valve turns properly. I could be that the handle has stripped, so only the handle turns, not the valve.
There shouldn't be any additional screens. Is there a valve under the sink that would allow you to shut of the cold water? That would be the way it was set up in the house...and maybe it got turned off when "winterizing"??
Good luck:)