My wife is 8 weeks pregnant and has been violently ill and bed ridden for 3 weeks she's taking diclectin but its not working. How do we stop vomitting?

OB. She needs to see a physician. Three weeks of any 'violent illness; deserves an md's attention.
See your OB. There are many meds that can help with severe n/v. Prescription meds such as zofran, compazine, phenergan, (promethazine) & vistaril are some examples. Otc meds such as unisom & vit b6 sometimes help. If your wife is really sick, she may need IV meds and possible hospitalization. Please call an OB for help.