Toilets, Sinks, Showers, Tubs and Disposals - Low Water Pressure

This may seem odd but ever since my water froze last winter I havent had any hot water pressure in the tub or shower. Could someone please help me troubleshoot this so i can find the problem and maybe fix it before this winter starts.

Rust scale was maybe in the pipes, if you have galvanized pipes, and freezing causes the pipe to expand which leads to rust-scale breaking free and then travels downstream and clogs where there is a restriction ( like at an elbow, or the transition points where pipe is downsized, at shut off stops/valves or at orifice holes in faucets.

This clog could be anywhere along the commonly shared hot pipe, AFTER another good hot water producing plumbing fixture, and your tub.

Since this is the only fixture doing this, we can rule out the clog being anywhere before or inclusive of the water heater.

You may not have any shut off valves for your tub, although sometimes there is. If you do, they could be up at the basement celiling leading to the tub, or be under the tub, above the floor, inside a removable access panel through the wall. If you do, you may have to take the valve apart and flush and see.

Beyond that point, you will have to take the guts out of the tub faucet (hot, anyway) and try to flush; Which you may want to try first.

Let us know how this saga unfolds, please.