You hear this all the time, that Germany had to invade the west and east when it did because Hitler's economic policies were based on more resources than Germany actually had.
I figure this question has two parts. First, was the economy really on the edge of collapse in 1940-1941? And second, was war seen as a viable method to fix this?
The German economy was absolutely in terrible shape when the war started. The government had borrowed massive amounts since 1933, much of it in off-the-books loans from German manufacturers. In 1939, the German government started paying off part of its debts with coupons for tax refunds.
The German government had burned through much of its financial reserves, even after the seizure of the government reserves of Austria and Czechoslovakia. The cost of borrowing was rising. When the war began, Germany was approaching a new debt crisis which - had peace continued for another year - would have created a new bank collapse and depression in Germany.
This is moot, because Germany's rapid military buildup and the associated debt was aimed entirely toward the manufacturing of a war in 1939 or 1940. Hitler believed a war was inevitable - that rival civilizations like America or the Slavic world would clash with a Europe whose leadership was in doubt.
Hitler believed that he was in power during a brief window when his rivals were weak enough to defeat. Britain was in decline, France hollowed out, the Americans distracted, the Soviets consumed with Stalin's purges. Hitler's intention, well before he took office, was to seize control of all of Europe and destroy the Slavs, creating a Greater Germany which could fight and prevail against the vast manpower advantage of a future Asian hegemon and the economic strength of the United States.
The path to such a future was impossible through peaceful means, and Hitler never intended to reach it that way.