I had a clogged drain so I shut the water off for both hot and cold under the sink before I did that the water pressure was fine. I cleaned out the clog in the pipes and when I turned the water back on the cold water pressure is fine, but the hot water pressure is very low. Help Please!

You likely disl;odged some debris from the stop valve and it is now clogging the hot inlet. Shut off your hot valve (stop) and disconnect the supply line just after the valve, cover with a towel and open close quickly to clear that line. Now reove and clean the cartridge or the stem, which ever you have, If you need more details then give more details on your faucet and we can help.