I don't know why everyone is going round in circles. The explanation is
quite simple. General relativity talks about curved space. Everything
follows a geodesic in curved space.

The whole universe (or more strictly the observable universe) did
indeed exist at the Plank radius. It expanded because the space around
it was (and still is) curved. A black hole is formed because the space
round it wraps round itself. The matter in the early (and now in fact!)
Universe was carried away on curved space.

Einstein put a lamda term in his equations. Lamda is negligable in the
solar system and in considering such things as Mercury and light
bending round the Sun does not effectively exist. Lamda is basically
why the Universe expands and started off expanding. Lamda means we are
not in a black hole.