Dear Modern Lass,
Look under the sink up at the underside of the faucet. If you have a
widespread faucet (where the hot and cold handles are more than 4 inches
apart) the hot and cold valves are connected to the center spout with
flexible hoses and I think the hose from the hot valve to the spout has
become kinked because the hot side valve got overtightened or the nut
holding it in place has become a bit loose.
Please let me know if this helped.
RepairGuy