How do I counter a trash rush against the extreme AI?

Hi guys, I was trying to beat the extreme AI yesterday using a scout rush BO. I was able to pick off 3 or 4 vils but then i lost my scouts to spearmen and skirms. The AI then counter attacked with 15+ trash units and the army kept growing in number. I tried sticking to the BO and advance to castle but the army eventually broke through my walls and caused a lot of idle time + vil kills and never recovered from there. What am I supposed to do against a trash rush while the AI is attacking my buildings? Make men at arms and delay castle? Use vils to fight? I was quite overwelmed with the spam