I liked being a high elf because I was taller than others but now Lydia is taller than me. I noticed that the old Nord at the Thalmor Embassy party was very tall, maybe he stole my height.

Are you sneaking?

I have heard few people have had this issue, though sadly I have no idea what causes it.

Also, I have noticed that at character creation scene, when you finaly accept your character settings, the pov of camera doesn't get adjusted for High elves. But when creating a shorter race, for e.g. a Breton the camera view get lowered to your charecters height.

If you play on PC you can fix this. Go back to a save where your character was the correct height. Go to third person, open the console, click on him/her and type "getscale". Should be 1.0. Go to the save where you feel you're too short and do the same thing to see if its changed to a smaller value. You can then type "setscale 1.0" to return you to normal.

I saved and quit the game then reloaded from that save and found I'm back to being taller than Lydia again, phew! that's a relief. Not much you can do when playing Skyrim on 360.