vibration at the clutch and rough gear shift

[Sean~328i//EastBay]

This morning when i come to work, i feel the clutch pedal vibrating more than normal, because normally i do not feel the zzz sensation in the foot, and then the gear shift was rough. upshifting or downshiftnig or movement into 1st gear is rough. It's like the collar gear does not engage and then goes into gear very roughly.
Previously i had the rough shift and i poured some more engine oil, as i found the oil had dipped below the level and it solved the problem.
However is this also tranny-oil related.

[cek2]

The clutch slave cylinder failure is a common problem with the E36. When failing it will display some odd symptoms. This is a relatively easy and inexpensive DIY job. get a second opinion.