Ths is where it can get sticky.If you are comfortable with checking your travel, I canwalk you through the steps. On the side of the tranny, there is a rubber port to allow you to check the bearing travel. This is really the next step I would take to find out if your problem is with the hydro or with the clutch plates. You do need a tool, its a Position Bearing Travel Guage Tool.
Now keep in mind that as the clutch gets used and abused, the fluid will actually be pushed back into the res. and make it appear as if there is nothing wrong.
When you take the measurements, then you will know if its a problem with the plates or not. Thats an important step.
In the meantime, I would check your whole system for leaks. Its not hard to trace.
Contamination in the line can also cause this kind of problem.
also have a feeling that you may just need to bleed the system. I have the steps I can email you for that if you would like. You need a coupler tool to do it. That may remedy the problem like that. May just be air in the system. It happens.