I am one of the few who can still hear my valve loud and clear 5 years later. Most of the time I'm able to ignore it and it becomes a part of every day background noise. But if I want, I can always focus my attention on it and count my pulse... The only times, for me, that it's really bothersome is when I'm having a hard time getting to sleep (my solution is to count the clicks instead of sheep), and when I have a nasty headache.
I'm not going to be one of those people who says "Oh, you'll get used to it" or "It will fade with time" simply because that's not how it happened with me (I'm sure it did for them, and does for nost people). But please take comfort in the fact that you're not alone, and the sound of the clicking will become a part of you no matter how much you hate it. I've often told this story:
When I was 5 I had a shunt put in which resulted in my hearing a constant "whoosh" sound with every heart beat. When I was 6 I stayed at my grandmother's house by myself for the first time and after being put to bed went into her study to tell her I couldn't sleep because my heart was "too loud." Fifteen years later I had open heart surgery and the shunt was taken down. For the first time I could remember, I couldn't hear my heart. It was a pretty scary feeling. For a while, it was difficult to sleep because it was TOO QUIET! Then, another 4 years later, I got the mechanical valve and was loud again. While it does drive me crazy, I know that if I went back to quiet there would certainly be an adjustment period...
Don't know if that helps, but I hope you feel better just knowing you've got others who have gone through the same thing.