I can empathize with the desire, but disagree with the solution. If you're weak and get pushed around by others, learn to fight. Don't just lift. Take up boxing, Muay Thai, Jiu-Jitsu, wrestling, or MMA. You can lift as well, but just "getting big" won't do anything for you in terms of defending yourself. I find that I'm at my best when I do a combo of both, but would take martial arts over lifting any day.