I figure I'm doing pretty well, I typically end up doubling my money within the first hour

Awesome.

, then losing it all by the end of it.

Uhhh.. maybe we need to define the term 'well' ?

call $2 BB in MP with KJc
everyone folds, but SB
SB raises to $25.
I call.

WHAT?!?! You are playing 1/2 NL and called a bet of $25 into a $4 pot? Toss that crappy KJs away. Lets think of the flops that you are going to be happy with: Umm... 3 spades.. Uhh... Three Kings.. two Jacks.. Anything else and you are probably looking into the business end of domination.

Turn Jd.

He pushes all-in (Around $36, I think for a second and put him on KJ, thinking I'm going to split the pot, so I call.

Now you are just being silly. You have KJ, the board has KJ. You put your opponent on KJ? Theres only four possible combinations of that hand left. This isn't a good read. His most likely hand is AA/AK/KK over the longterm.

I believe the flop is where I should have made my move, but I'm still not 100% sure. Anyone have any help they can provide.

Your major Major MAJOR error was pre-flop with calling a large bet into a micro pot. Once you did that, you are pretty much committed to showdown when you make TPMK and you arent going to shake mr agressive off his top pair so however the cards fell is inconsequential.

But please, understand that your preflop call is easily a long term losing proposition. You will be used and abused by players with monster pockets.