Hot water pressure problem, cold water ok

I am currently having a problem in my home that just started today. I came home from work to find that I had no hot water pressure at all. Well, to begin with, there was a trickle, now there is nothing. I do however have cold water pressure that is like normal. Can someone please lead me in the direction I need to go? I am thinking it is the water heater but not sure. There are no fuses or breaker problems.
Thank you

Open and shut the cold water inlet valve to see if there is debri buildup in the valve, this could be the issue at hand.

corroded on top

its a good chance that the water heater has corroded shut.

depending on its age, the nipples on top of the heater jsut lime up
and need to be rheemed out or the heater might as well be changed if it is
over 12+ years old.