it might help if i said that it describes two aspects of the same thing, splitting up as indicated, also rearranged slightly
I am a house of lies,
A flimsy construction,
Changing all the time,
I am loss, pain, and regret,
I am happiness, lust, and love,
I am hard and soft, short and tall,*
I am the world through different eyes,
I exist in many forms,
I am what you see and know,
I know all,
I am truth,
I am known to all.
*this line i find describes quite well that aspect of the thing