Need help playing Vanguard Onslaught

Hey everyone.

I played my nids since 11th edition and they stil suck... So I am asking for help.

I like vanguard because it has lots of infantery. I add the lictor detachement with it. It is not great but fits I guess. So I basicaly I play 3 bricks of Stealers with broodlords, 6x warriros with an alpha, 6 zoans with a neurotyrant, 3 lictors and 1 desthleaper.

I am not able to score points. I can be turn 1 in my opponents face and kill stuff. But most armies can retaliate without effort. So I can either go in or stay back. When I go in, most of my units are dead by turn 2-3 and I cant do stuff anymore. When I stay back and wait, I miss 2-3 of points and cant come back.

So, what can I do? What do I do?