i've only been taking yasmin for maybe a week and a half, and i'v...

i've only been taking yasmin for maybe a week and a half, and i've noticed that my mood has been wayyyy down low. i suffer from depression, and i've been on antidepressants for a couple of years, but i've been a lot better for a while now. but over the last week, i had one *fairly* negative event last week with a guy i'd been seeing and suddenly it's completely deflated my whole life... i get home from work and basically curl up in a fetal position on the couch with virtually no desire to budge for the rest of the evening. my thoughts and outlook have been really black and hopeless and i start crying at the least negative thought because every little not-so-great thing blossoms into my life being completely pointless. plus i'm pretty lethargic and discombobulated. two questions: a) could one week on this pill really cause all this mayhem, and b) can i just go off of the pill? -- as in, can i just stop taking them and it won't mess my cycle all up? i haven't been on the pill for about 8 years, so i can't remember how much it affected me back then (it was ortho tri cyclen) but anyway, any input would be greatly appreciated!!!