Please help, need advice (long)

First of all, I would like to say "hello" to everybody. This (I think) will be my first post on these boards (I - apparently - unsuccessfully attempted to post a similar message last night).

On to the problem:

I am contemplating the idea of becoming a "professional" poker player. I don't really know what the exact definition of a "professional" poker player is, but I think of it as someone whose only source of income is playing poker on a regular basis. And this is what I hope to eventually be doing.

I started playing Texas Hold 'Em approximately 6 months ago. My friend, who has been playing for years and knows quite a few people who play semi-professionally, introduced me to the game. I was never really into "gambling" before I started playing, and I really don't think I would be interested in any other form of "gambling" besides Hold 'Em. I'm just not a "gambler." The only reason I play poker is because I am good at it, and I find myself making over ten times what I make at work when I am on top of my game.

The only problem is that I will occasionally have a bad luck streak, where the cards just don't work. I am an aggressive player, and sometimes I just don't get the cards that I expect to come. Some nights, it seems as if that's all that happens, and I lose my entire $300 stack in just a few hours (I play 6/12 cash games at Commerce Casino, CA).

Does anybody have any suggestions/advice for me? Should I go "pro?" Should I just play part-time? What kind of bankroll should I have for playing 6/12 games on a regular basis? Is it better/easier to play online versus brick-and-mortar? Am I just a newbie fish that should get the heck out of your world?

I would appreciate some constructive criticism/helpful advice. I would like to thank anybody who helps in advance. And please, no jokers. I am serious about this.


Edit: Don't be afraid to ask clarification questions. If there's anything you'd like to know about this subject, just ask. I will answer any intelligent questions.