hey Xaw,
Well i m sure Dayle would have solved your query there but here is what i think if it make things clearer (or worse

)
Your opponent was most probably expecting your team to dominate them through fast paced attack (high tempo = more chance on goal therefore more goals) So they played a counter attacking tactics. When playing faster tempo, you will know you are facing a counter attacking tactics when u seems to loose ball too much and your passes arent completing. So when u went defensive, your opponent had a better hand at the game and of course u just invited them to hang around in your park so they took advantage and kept on scoring.
Think of it like neutralizing effect. If u wanna neutralize an attacking stance, you dont go defensive because you are paving way for them to attack.
As Dayle suggested, i would have probably went attacking with slower tempo because simply, they wouldnt catch you off guard too often and u got them marching to your beat as they will be playing defensive.
And finally you should have noticed that you were at home not away. Therefore you shouldnt even think about defensive or counter attack as you are the dominant team here and you are at home.
I hope i helped and didnt make it worse. I m sorry if i have repeated Dayle's or anyone elses point.
Thanks and have a good game