Trouble selecting first gear and reverse

I bought this car at 13,000 miles and the gearbox was a dream to use.

Since then the clutch has begun to get heavy at a very quick rate to say I have only put an additional 5,000 miles on since may (now December).

I do not ride the clutch or over rev when pulling off so I am at a loss to explain this.

As well as the above my main issue is that the car will not willingly go into first gear sometimes and has to be "forced". Every other forwards gear is perfect other than first (this includes while stationary and the vehicle is moving with the clutch down).

Reverse is also now an issue, with the clutch having to be "wiggled" to get the car into reverse.

Can anyone shed some light on these problems and what the cause may be? I do not think it is right that I take away a car that is perfect initially and then have all these problems eight months down the line (especially given the cars low mileage and is a diesel).

Thanks