It is likely the hot water valve(s) are not turned on all the way. Try adjusting the hot and cold valves to achieve even pressure. Next, make sure your hot water tank is filling to the top and that you do not have a leak in your hot water pipes.
The water pressure form hot to cold can be many things. One thing is that it takes your water heater longer to build tmep which in turn creates slow pressure.
Hot water has to go further, from the supply to the water heater vs. cold water which comes directly from the supply. There is also pressure lost in the water tank when it travels to the water demand which loses PSI.
