Colt BJ 2009 – How do I detect defective coupling?

Hey dear community, I need your advice: I drive a Colt BJ 2009, with currently more than 387,000 km on the speedometer. Since the last / penultimate week he drives somehow differently. One feels as if the force is not transferred to the wheels. I have not yet noticed a real “slip” of the clutch (engine throbbing, speed increase but you will not be faster) You have to say that this is still the first clutch and that neither of me, nor of the previous owner times a (I own the vehicle since 2014). It’s more like it takes him felt much longer to get to speed. From 100 km/h it gets really loud and a funny vibrating comes to it. I’ve also tried to provoke the car, no matter how fast I let my clutch pedal come, I just can’t get rid of it – but my clutch pedal is also felt on the last few cm pedal path and nothing happens before. can drive even in the 5th gear with 10 km/h through a gyro without the engine running out or that it starts stuttering. Does this indicate a defective clutch, or could it be something from the gearbox? With the km performance of course the clutch exchange wants to be well thought out at 387,000 km, but I still like to drive it and the used car prices are really heavy at the moment. Besides, the Colti has never let me down great or a little bigger it had, everything was always rather wear parts and thanks to LPG system also very cheap in maintenance (and I have to drive at least 150 km daily). I thank you in advance for your answers LG Speedy 302