Did I destroy my clutch?

[cornontherob]

If it starts slipping noticeably, get the clutch and flywheel replaced. I'd recommend a dual mass flywheel. For future reference, holding the clutch halfway out and using it to stay stationary on a hill will burn it out very quickly. By doing that you're essentially using the clutch in the same way that a brake works. This means that the clutch is slipping on the flywheel, whereas normally it's either completely engaged, not slipping, or completely disengaged, also not slipping. Use the brake or handbrake for hills.