The cash game has been rough for me as well, I've had both winning and losing streaks, and analyzed why in both. For me it all comes down to, knowing when to play, when to quit and disciplined bankroll management.
I've had to confront my personal demon and admit I don't have the bankroll to play cash games, I sometimes will play for fun but "limit" my investment to what I can afford to lose. ( I am the fish you want in your cash game )
Nickel and dime poker bores me and I play badly, 1/2 limits is what interests me at my current level of thinking, the max buy-in is 200 and I figure I need at least 2000 in BR in order to keep records and adjust my playing or not playing to effect a profit.
But life is what it is, I have to buy my baby new shoes, pay the mortgage and keep my life comfort/quality levels up to a certain standard. Until I can afford to leave 2000 alone and prioritized for poker only, I play tournaments and am sharkbait in cash games.
I stay within my BR managment scheme in tournament play and I do ok, I'll stray into a cash game rarely, sometimes win (I call that luck), sometimes lose (unlucky or bad play) until I have a proper bankroll I can't honestly say that I "worked" it with skill for a profit. Confidence is so key to how you play, constant monitoring of your record/journal and game adjustment where necessary helps that confidence.
Self-control/BR managment = Shark
Gambling/no BR management = sharkbait
Right now as it stands if I lose a cash game I can't complain, I'm gambling sometmes I lose sometimes I win. Once I win a big enough tourney and my life is in order, once I set up the proper bankroll I'll have better confidence in developing a sharks attitude rather than gambling.
There's more to the poker addage than whats on the surface when they say; "How well you play poker is scored by a lifetime." As in the larger context of your life, the closer you are to the "now" in poker relates to your bankroll. How big or small is it? Where did it start, where is it now? Which way is it going, up or down? Are you being honest with yourself?
Oh oh ... I'm getting too philosophical .. better stop here.