Here's the quick power steering 101.
The pump is powered by the main belt, and it constantly pushes fluid under pressure towards the steering rack. When the wheels are pointed straight, there is equal hydraulic pressure to both the left and right side of the steering rack. When you turn the wheel to the right, the valves change position, one opening a little more and one closing a little more, so that more fluid pressure presses against the LEFT side outer seal and pushing the left tie rod out. Since the tie rods are behind the center of the steering knuckle, this turns the wheels to the right.
If your outer seal(s) are shot, the rubber boot(s) will eventually separate/blow out due to the pressure of the fluid. You will start to notice fluid loss either from seeing it on the ground, or hear it as cavitation or whining from the pump.
If the inner seal(s) are shot, I would think ... Though I don't know ... the difficulty steering would be equal.
In my case, I noticed the boot separated on the right side before I noted any other symptom.
You may have a stuck valve, or other blockage, I suppose, it might be gunk built up in older fluid. I had a blown right outer seal, and as long as I had fluid in the system, there was no difference in ease of steering to the left or right.
The problem is that you can't see the valves working or not without pulling the gear. If you did pull the gear, you could rotate the shaft and see if there was a problem there. But then, at that point, you may as well put in a new rack.
So you can have it looked at, but outside of a blown-out boot, I don't know that it is possible to determine conclusively what the issue is from a basic visual inspection. The system is entirely mechanical, and there's no sensor reporting or electrical feedback you can get from a scan tool.
Probably not the pump. Doesn't sound yet like outer seals. Try new fluid, and if that doesn't do the trick shop for a rack replacement (DIY is a PITA but doable) and drive it as long as you can stand it.