I'm going to clear some things up...
If you are getting a headache or getting a sick feeling from smoking weed it is either because
A) It is mexi brick schwag nastiness
B) or it has mold from poor storage (too much moisture in a closed environment)
If you have properly cured weed (dried out to the proper moistness) and then keep it in a mason jar out of heat and light, weed can be stored for YEARS and be just as dank as the day you put it into storage.