Yes, I will Grant you that, but I give superior credit to the forces in blue who STUCK it out. There was incredible pressure to toss in the towel, but Americans were made of sterner stuff then, at least the elected were.
Yes, the Confederacy executed grievous casualties on the North and there's probably not a town above the Ohio that didn't pay enormously to keep the Union together. You may take some (very) small comfort that you majorly bloodied the other team even thought you lost the game.
There was a paper posted by someone who did the math. The South was doomed to failure from the get. Just like Yamamoto is supposed to have said something like: "I'll give you victories for 18 months, after that all bets are off."
There is no way on God's green earth that the Southern Confederacy could've pulled it off without major foreign intervention. Failing that, it's a miracle you got as far as you did.