It sounds like the same problem I had with my 95 GSR, it was very hard to get into gears, it would grind when going into gears, and towards the end, it popped out of gear. When I brought it to my friend to fix, right away he knew it was the clutch and said it needed to be replaced.

After it was taken out, the springs on the clutch disc had been grinded til it was flat and not round like the spring used to be.