Absolutely bad idea. Steroid creams suppress your immune system so its not a good idea to put them on a skin condition thats caused by a virus. Stop using steroids now. Some chamomile baths would help it a bit. And go to your pharmacy for some cream like acyclovir ( zovirax ) to apply although this should be take orally to be more effective, only a doctor could prescribe pills for this condition. Do something!!!
No they would not help herpes sores. 1% coritizon cream with aloe is good for itchy skin.