Hand 1 is fine. looks like he had a small pair above the board. I rarely ever reraise AK and sometimes fold it preflop. It simply has little value in a deep stacked game. In 25NL it is a big hand because worse aces will pay you off, but typically if you are playing a big pot with AK, you are losing.

Hand 2: If this c-bet gets called, I am generally done with the hand. Pot sized river bets (as well as overbets) are almost never bluffs, unless you have some previous knowledge that your opponent is capable of suck a bet. He checked behind the turn because he was afraid of a check raise.

Hand 3: The reraise is not enough to make you fold. You are good here more than half the time, the other times you lose. Get used to losing these hands.

Hand 4: This fold is fine. You don't want to play for stacks on this board with one pair.

Hand 5: I lose WAY more money on this hand than you do. Feel lucky he didn't re-raise your turn bet.

How many hands is "2 days?" I lost 5 buy ins at 200NL in my first 2k hands there. It happens. I have lost 2 buy ins in one hand before. It happens. Poker is a game of luck with just enough skill that some of us can make enough profit to beat the rake. Most don't. Play more hands, get more accustomed to the swings, think of poker as a hobby, and not a source of income. It takes years to get good at this game.

Good Luck.