Ok first it's only been a week, a good cure is going to take at least two weeks, longer depending on the strain and density of your buds, be patient give it some time.
Now there are several things that make weed harsh. The first thing is weed that was either dried too fast or is too dry. You mentioned that your weed crumbles when you break it up, it shouldn't be that dry during the first week of curing. Your buds have to be slightly moist to cure, if they are totally dry they are not curing. You may want to try to get them to absorb some moisture. After a good cure you buds shouldn't be crumbley they should seem slightly pliable, you shouldn't be able to break it up with your fingers. It should burn slow but evenly in a blunt or joint, it should go out if no one is toking on it.
Did you flush your plants prior to harvesting? Leftover chemicals from nutes can make your weed harsh.
Lastly did you dry your plants in the dark and are they away from light during curing? Drying and curing in dark areas allows the process of photosynthesis to stop. It allows the chorophyll, sugars, starches, and nitratres (all products of photosynthesis) to break down faster. The process of photosynthesis doesn't stop when you cut the plants down. All the products of photosynthesis can make your smoke harsh; they are also what cause you buds to smell and taste like grass, leaves, hay, etc. You'll notice that after drying and curing youor buds will start to lose that
fresh green color, they will still be green but they won't look "fresh". You know what I mean?
Also to grind, who may think curing is bs. I assure you it is not. Not only does it make smoke less harsh and improve the taste, smell, and look of yoou bud, it increases potency by allowing the non-active acids of THC to be converted to the active form.
https://www.rollitup.org/1512312-post63.html
Pictures that show the difference ^^^^
Entire thread with discussion on it:
https://www.rollitup.org/harvesting-curing/120624-want-bag-appeal-curing-matters.html