I have owned a TCP for a couple years now and the only issue I have had on mine is shooting Tulammo.
When you say it is hard to rack it how are you doing it? Putting your palm on the top of the slide thumb to the rear and pushing with the hand on the grip? Pinching the back of the slide with thumb and index finger, pulling back and releasing? I also would not recommend changing the spring.
What is your body type? Male, female, slight build, average, large?
Gun ownership/knowledge/usage background?
Need more info....