I almost always play 1/2 at the casinos
, but to be fair 2/5 isn't much harder. I think 2/5 is lower variance for a more aggressive style of play. But you can play a very specific game at 1/2 which really focuses on value and making smart folds with only marginal aggression and do pretty well.
Making $300 a session is not a reasonable expectation (depending on how long you play). I know a guy who plays very regularly - very nearly everyday to make money - and he makes around 5k a month. That means that he makes about $175 a session on average, he's pretty good and likes the easy games.
Moderate your expectations a little I think.