Weird clutch problem on my Honda civic vti 99 model m/t

Hi guys! My car is a civic 99 model m/t. In the past few days nagloloko ang clutch ko. When I start the car and drive for about 3-4 Kms ok naman, pagrelease ng clutch pedal nageengage na sa bandang gitna, just like normal. Pero if I drive for more than 4 kms biglang tumataas yung engage point ng clutch pedal at medyo tumitigas ng konti . Malapit ko nang irelease yung clutch pedal dun palang mageengage. Medyo maulan dito sa Baguio lately, di ko alam kung may nabasa sa system or somethin pero wala namang baha. Any ideas guys? Sana po di magulo yung pagkadescribe ko ng problem sa car ko. Your inputs will be very much appreciated!
Thanks and God Bless!