Did I overstate my values on the following bidding?
Normally your 2H bid would show around 10 points in that situation, so the question is whether you consider your hand to have that value.  You have 8 HCP, plus some bonus for the heart length; so maybe you could stretch that to a 2H overcall. I don't think I totally mind it, but it's aggressive for neutral vulnerability; and you shouldn't mind the game push by partner after it.  Personally, though, I wouldn't bid it.

You do have a legitimate alternative that you're discounting, though, which is the negative double.  Normally that shows 4 hearts and 6+, but it can also be used with a below-game level heart hand with more than 4.  It's not an ideal bid for your hand, of course, but it keeps the auction lower.  Imagine this auction:

1S - 2C - X - P
2D - P - 2H - P
2S - p - P - P


Your partner might bid 3D instead of 2S, and you'd pass that as well with no preference between the two I imagine (or you could bid 3S, clearly not wanting a game then).  

Either way you stop well short of game, and you adequately describe your hand, as that's the way you bid 6-9 5+ hearts.  The 2H bid after the X perfectly shows your hand, your partner knows what you have, and you end up in a reasonable contract.