You know it just cant be done, 7 meelee. I dont know that map, but looks like there is only one bridge to your base ? If so, you can hold on for some moments. In start. But later on, when cpus start to attack with flyers .. no chance.
You know meelee means that computers sees whole map and they play as they are one player (they help each other). So no chance. When they have some small group of force, lets say 8 zealots they send it to you. Mutiply it by 7 players ... total carnage. You cant hold that. Or you have to only defend yourself, no expanding.