Please, I am trying to figure out the exactly meaning of "build me up" in the following lyrics :

Invitation (Rolling Stones)

Everything I thought was mine
But if your love again is longer
Why drag this thing out much longer?
Yeah I'll be ahead
If I could bring what I...
You build me up just to let me down
Let me down
You seem to love seeing me falling down....

Build Me Up Buttercup (The Foundations)

Why do you build me up (build me up) Buttercup, baby
Just to let me down (let me down) and mess me around
And then worst of all (worst of all) you never call, baby
When you say you will (say you will) but I love you still...

thanks in advance.