Rakuall, as others have said, we all sympathise with you, because we've all been there. Your first Edition-Change is kind of like your first breakup. It seems like the end of the world, you'll never love someone (in this case something) as much again, etc. 99% of the time, you get over it, and the track record with edition changes have been rather good over the years. Much better than the average track record with breakups.
Worse case scenario, you don't like the new edition. Thats fine. You can still play 5th edition with your friends (though depending on where you game, the 'Man' may get you down). I know my brother and i recently hauled out the ol'3rd edition and played a game with those rules. I somehow suspect it'll be many years before i feel nostaligic enough to go through THAT again, but just because the game moves on, doesn't mean you have to.
The likelyhood of a new edition ruining 40k (or Fantasy for that matter) is pretty slim. If anything, it'll be the constant price increases and lack of overall vision which does the game, and the hobby, in.