NL50 (.25/.50) is quite an advanced level. Players here might have played 50,000+ hands of online poker, a lot of experience. They basically profit well from players like yourself, who have played a bit of live and have very little experience by comparison. My advice is to drop back to NL10 (.05/.10) for at least 5000 hands to gain experience. After 5000 hands you should have a fair idea of how you are going, but some would play much more hands before moving up to NL25.
Post some of your bad beats to the Hand Analysis section. If they trully are bad luck, then you will get the good luck your way at some point. But more likely there will have been ways you could played some of these hands differently to actually win it, or at least lose less. There is a lot of excellent information in the hand analysis section, you could do a lot worse than reading all the hands and responses that get posted there.
Poker Tracker will keep a good eye on your game, here is an article about some of the key problem spotting areas (sorry, another forum):
The 2+2 Forums: How to use Poker Tracker.
Once you understand the key factors in Poker Tracker, Gametime+ or PAHUD will help identify how your opponents play (shows their stats as you play them), and what hand they might be holding this time.