First of all, remove and clean the flow softener. It is located right at the end of the tap and is a very common reason for such problems. The thing get clogged with fur and should be rinsed in vinegar to remove it. If the pressure is still low, even without the softener, invite a professional  plumber over. The kitchen plumbing might be clogged somewhere.  A professional plumber can locate and fix the problem with minimum damage and replacement to floor/kitchen tiles.