Night time bra?

How long do I need to wear a bra at night? Its been several weeks since the lumpectomy surgery and this nasty bra is becoming the most uncomfortable item of clothing I own. One morning I expect my bottom half to be severed from the top. I have nightmares about being strangulated across my midriff. The little hooks and eyes are working in my favour though; they pop open during the night (never all of them). This happens during the daytime too. I'm convinced my breasts are conspiring to escape the restrictions of the nasty bra.
Please, someone tell me I can go to bed in my natural state, SOON!