A sharp downturn in revenue after sea attacks by Yemen's Houthis diverted shipping away from the Suez Canal has struck a painful new blow to Egypt's already deteriorating economy, adding urgency to the need for reforms and help from abroad. Nearly all Egypt's main sources of foreign currency - natural gas exports, tourism, worker remittances from abroad, and now Suez Canal revenue - have all come under recent and severe pressure. Egypt needs foreign currency not only to import essential commodities to feed its people but also to repay $189.7 billion in foreign debt, most of it racked up over…