I may have to disagree about the galvanized piping here, not that I think it is good, but I'm not sure there is any. But first I have to ask the question, have you checked for hot water flow at every faucet? That includes laundry.
You have two branches coming off the water heater so I would think that if the problem was with a galvanized section, it would only affect one of the branches so at least one faucet would not be affected by it.
If every hot water faucet is slow, then the problem is before the tee in the hot water system, that means either the heater itself or the inlet valve. If that water heater is truly a 1995 model, you have gotten about 11 more years than I got out of my identical model, however I am on a well whose water has a pH of 5.5, but still I will never have another one of those brand in my house again.
Having said that, I think the globe valve is the problem. They are hardly ever closed and after a while, the rubber seal can start to rot away, become unseated and start blocking the flow. Quick fix is to shut the water off to the whole house, then pull out the stem by taking off the big nut around it and replacing the rubber washer (seal). Use a kit made for that valve because you will need at least a new screw and possibly a new seat.