You're having too much, and/or not eliminating it properly. You'll have to figure out ways to get it out of your system, or increase your blood sugar if it gets too low (though blood sugar rushes can also be bad). Drinking liquids or eating fruits might help. Or maybe other foods. Weed has a diuretic effect, as well as increasing insulin sensitivity, so you will need enough liquids and maybe some sugars. THC binds with fats, so perhaps having fatty foods will help, or maybe it will do the opposite and make it harder to eliminate it. I don't know. If nothing else works, try going to bed. If you manage to fall asleep, you'll be alright when you wake up.
Being in a safe, comfortable environment and situation (social or otherwise) also reduces the chances that you'll get this.
Ultimately, try and figure out if you really need weed, and why.
I used weed a lot for 5 years, and was a total pothead for 2 of those. I've since quit over 4 years ago. I did have a bit after quitting, but I haven't touched it in over 3 years.
In restrospect, I was probably using it to manage my anger issues, and to manage my blood sugar spikes caused by a poor diet. It also made it easier to be a social hermit and not worry about it.
I don't think I will ever go back to it, or any other drugs. (I also used a lot of LSD for about a year, inbetween pothead phases)
