Yeah, it's pretty bad--but we'll live. If three consecutive terms of Republicans (1980-1992) didn't kill us, four more years of the Shrub won't.
If you want to radically change your life in response to Bush losing, then IMHO your best bet is to go through some sort of formal study program in political science or activism (you would have time to do a master's, if you're already a college graduate) and volunteer for your nearest viable Democratic Senate candidate in 2006. We had far more seats up for grabs than the Republicans did this year, five retirements in the South, and we've still got about (I say "about" because two races are still undecided) 45 votes.
Rehnquist is the third most conservative justice on the Supreme Court and, in rare cases, he actually votes to the right of Thomas and Scalia. Whoever Bush appoints, I find it unlikely--given that there are about ten moderate Republicans in the Senate plus 45 Democrats, and Bush would need 60 votes to really push a right-winger through--that the new justice will be to the right of Rehnquist. My bet is he'll probably be slightly to Rehnquist's left, which will indicate a net shift in our direction. (Early prediction: Bush nominates Alberto Gonzales, and elevates Clarence Thomas to chief justice. Pessimistic scenario: Orrin Hatch as nominee. Optimistic scenario: O'Connor as chief justice.) The two justices to watch are John Paul Stevens and Sandra Day O'Connor; Stevens would be 88 years old in 2008, though he's in good health and loves his job. I think O'Connor would be 83 or so. Stevens is a left-leaning maverick and O'Connor is the Court's true swing vote, so if Bush replaces one or both of them, it could actually represent a shift to the right for the Court--a significant shift, if the Republican count in the Senate actually increases in 2006 (which I seriously doubt, because at that point the shoe will be on the other foot and more Republicans than Democrats will be up for reelection).
My other piece of advice to you is to sit back and enjoy the Republican Party schism that's about to unfold. Now that they have a clearer majority, the split between libertarian Cato Institute Republicans and theocratic Christian Coalition Republicans will become more pronounced. If we're smart, we'll be able to snatch some people from category #1 and marginalize the Republican Party like we did in the 90s. Personally, I would like to see the Democratic Party become in effect the Social Libertarian Party, with diversity on fiscal issues but unity on social issues. Our party has already tried the reverse, and it didn't hold.
Obviously I'd rather have seen Kerry win and the Democrats take a majority in the Senate--I hoped for it, I prayed for it and, frankly, I expected it--but the Republicans didn't turn tail and run when they got stomped in '92, and the result was a '94 victory that has given them 12 years of congressional majorities. There's no reason why Democrats shouldn't be ready to roll up their sleeves and do just as well.
Cheers,
Tom