Leaves dying and shriveling up (pics)

One of my widdow plants has been giving me alot of problems the last month. Three weeks ago there was a nitrogen deficiency, The leaves were yellowing and a few of the top leaves were starting to shrink and shrivel. Now all the yellow has gone and now the leaves are starting to shrivel all over the plant and i need to stop it. Please help it is a female, and it is really close to flowering.

really cant help ya because the growfaq is down its a deficiancy i juss cant remember which one

i think its a mg def.

no not a MG i think potassium try to take a closer pic of the leafs that are showing the symptoms so we can get a better look