I have a Kohler faucet (K-15160). All of a sudden

Check that it's hooked up correctly. I've seen this exact problem when the hot water is hooked to the cold side of the valve.

On the front of the faucet handle, there is a small plastic cover with an emblem on it. Gently pry it off with a sharp knife blade. Next you will notice a small "allen" screw head. Remove it by turning it counter clockwise until it's loose. (lefty loosie - righty tighty) Lift the handle straight up to remove.

Kathryn, the kink could restrict flow of water because there is so much less room. To remove the kink you could try pressing the two sides of the kink BUT that is risky. Have a replacement ready in case you damage it further. DO ALL THIS WITH WATER SHUT OFF. If you manage to straighten the kink even a bit more, water will flow better.GL

yes any bend not made properly will affect the flow also makes a week spot.

after you take the handle off,the hose needs to be taken off for the faucet body to be pulled up to get at those o-rings

Sounds like you may possibly have some sediments in the screen on the spray head. When you pull the head out you can disconnect it from the flex supply line and see if the water pressure is okay with out the head connected. This will either confirm it is in the spray head or valve body.

they get gunked up with grease and junk, and or mineral deposits from well water---unscrew the aerator housing(underside of rounded pullout part) inspect and clean all part making sure there are no cracks in plastic junk used today...also noting correct placement of parts

There are two possible things to look at.

Because you say "misaligned" and "frozen" it could be the handle is not set to the correct position.

There is a set screw holding the handle in place. It is a hex key I believe on that tap. Loosen the set screw and lift the handle off. move to the correct neutral position and set the screw.

If this does not do it and you are getting nothing but hot. The ceramic ball and washers could be stuck or broken. While the handle is off remove and inspect them. They should move freely in the socket. Replace or repair if necessary. Just take them to a plumbing store they are common parts.

Hope this helps. Please rate the answer if it helped you.

could be a number of things.
most mixer taps have flexible braided inlet hose's make shure there not kinked.
also there may be built pressure reducing valves,usually removerable,a plumbers job really.
is there servive valves on hot and cold if so make shure there fully on.good luck ,any qs ask

pull out the spray part and tighten the nut around the hose or take it loose and replace the washer