We had a leak from our kitchen sink, one of the connection pieces to the pipe came off because of shotty work, apparently the entired pipe wasn't sottered or something. Anyway, when this occurred water was flowing from under our kitchen sink and flooded our whole kitchen and dripped down into the basement. We just moved into this house so we didn't exactly know where the shut off valve was. I was on the phone with a plumber and we eventually got the water shut off, they came out and fixed it and everything in that sense is fine. But while we were trying to shut the water off we were trying basically anything, we turned a few valves on the hot water heater and the boiler and now we have low hot water pressure on our kitchen sink, and there is a constant sound of running water through our pipes. We attempted to put the valves back to where we thought they were but this didn't help. Can anyone help?

Did you open any valves that were closed? Ie: an outside spigot. You can try shutting off all valves, then open them back up, one at a time. After opening each one, go and try EVERY faucet, shower, washing machine, etc. to see if you found the problem.