Need Soccer Advice?

Hi I Need Some Advice On Soccer, Ma Height is 163 n ma position is striker. well i got no problem on speed, but i just need advice what should i do wif ma size? cause i'm short n small. n usually big defender easily body check me off. so thought of work out on ma body. is there any effective way to do it without going to the gym? N Any tips For A Short Striker Like Me? Thanks Alot Guys =D