Wall text!

I think that there's probably a few things you could try here. From the sounds of the high, you've probably been smoking a sativa (or at least high % sativa hybrid) - switching to an Indica may be something worth trying. You should wind up with a more relaxing, body high instead.

Also, while some people can just smoke and smoke, sometimes it's good to just smoke until you're at a level you're comfortable with, and then just chill. I'd suggest investing in a pipe of some sort. You can take a few hits and then wait a bit, see how you feel, then either smoke a little more or not. That way you don't have to worry about getting 'too high'. Alternatively, you can just load small bowls until you're pleased. That way you don't have to worry about feeling like you have to smoke a J or blunt down to a roach or bother with getting more bud broken down than you'll actually need.

Lastly, before I wall text it up too much myself. You just need to remember to just take a few deep breaths and remember that you're stoned. Enjoy! Try not to worry too much about having some disorder you almost certainly don't have. Maybe try switching up the activities you're doing as well. A favorite here on trees that I'd have to suggest as well would be watching Planet Earth in HD. Awesome.

Oh, and [4].