Wow, if you gave up just posting on a forum, I'd hate to see how you fair in marketing and shit that is actually difficult. That's like saying you gave up trying to start your career because you couldn't figure out where your name goes on your resume. I mean good God, find something better to complain about, man.
Everything you encounter in this industry is going to challenge you, even the damn forum apparently. So, figure out what you did wrong and correct. Take it as a mini-lesson. Something in your post is triggering the spam filter - maybe it's a link or a specific word - so figure out what it is, change your post (read: method), and try it again (read: implement) to overcome the obstacle.