It's simply that
we are moving fast.
It's that simple. The Earth is moving VERY fast around the sun, so it is not "dragged in".
If for some bizarre reason the Earth slowed down ... it would move in closer to the Sun. If it stopped moving - it would fall directly in to the sun. It's that simple.
Note that this is exactly how satellites work. (I mean the satellites we launch to use for TV communications and the like.) If they need the satellite to move down closer, they simply slow it down a bit. To go up higher, you just speed it up a bit.
So it's that simple.
"I think there must be a repulsive force."
There's no repulsive force ... we are quite simply moving very fast!
Note that, quite simply, say you want a rocket to "get away from" the gravitational power of the Earth ... what do you do? Simply make it go very fast! It's that simple.