This is why I keep telling people not to marry out of pity, while dating, u will see where there is lope holes, try to concider if u can cope, if u can't, just let go. Sex is one of the ingredients that keep marriage alive, so many couples have break up because of it. I advice u to take it easy with her but make her understand how important it is to u to avoid going outside for it, but don't threaten her.