A lot of bud smells musty/earthy and has a darker color to it, mostly occuring when it is grown outdoors, there is no way for us to tell what is wrong with your bud (if anything) but it is probably just outdoor bud and the musty smell could just be in the strain, i had plenty of nice green buds smell musty before and also had plenty of darker, musty outdoor buds that were not moldy, although what you have could be moldy or old bud, if it was really moist like you say it could very well be moldy, is it harsh when smoked? Does it taste or smell funny? Is there any white spots or white fuzz on it? If it hurts your throat/lungs and gives you headaches then it is probably moldy, try drying it out and put it in a jar for a few days, also get a magnifying glass and try to see if there is any mold on it before smoking anymore.