It sounds like you're mistaking your understandable emotional response to taking a few bad beats for a rational case why it's impossible to win at poker. Either you really can't tell the difference -- in which case you need help learning why your case isn't really as rational as it might appear -- or you can tell the difference, but you're just looking for affirmation that you're not as bad a player as your recent results erroneously indicate. I don't mind people using this forum to fish for psychological pep-talks -- part of being a beginner is not knowing how to give onesself the necessary psychological boost -- but that's a different thing than trying to make a case that poker is theoretically unbeatable.
The flaw in your post is that it's all biased in the downward direction. Yes, sometimes you work all week to make 100 big bets and lose it all in a few hands. (Your assertion of losing it in five hands, however, is suspect if there's a standard betting structure and four-bet cap.) Sometimes you dribble chips for hours and then win it back -- and then some -- in a few hands. In fact, I'm convinced that this pattern is part of correct play, because correct play makes you the favorite to win the biggest pots.
Sometimes your AA loses to 83s when the board comes K73-5-3. Other times your AA beats 83s when the board comes AT5-9-5, with the five on the river making your opponent's flush. You remember the first occurrence because it was so undeserved, but few people stop and think of all the times they won outrageously big pots with aces, because aces are
supposed to win. And indeed, anyone could win that huge pot with aces-full, but not anyone could hold onto those winnings by not wasting them on playing 83-suited all night!
You're correct that the rake is a drag on earnings, and if everyone played equally well they'd all lose to the rake. But there's plenty of emperical and theoretical evidence that bad players put more money in the pot than the house takes out.
You probably need to take a break, rest up from the bad beats, read a couple of
books, and come back out ready to take on the world.