I think it sounds like the nozzle at the end of the spout. If you look
underneath the spout, you should see a plastic nozzle with loads of little
slots/holes in. The outer set are normally for the cold water and the inner
set for the hot. If they are scaled up, there's your problem. Some nozzles
just unscrew and you can clean them easy. If not just poke something thin to
each one to clear it.