So I'll start clearing up the bottleneck with something short yet powerful.
In Parshat Bo (Shemot 13:2), Rabbeinu Bachya says the following:
And therefore, we find that the Navi [Yeshayahu] likened the Love of the Holy One Blessed Be He for Yisrael to the love of the mother for the child.
As it says (Yeshayahu/Isaiah 49): "Shall a woman forget her suckling child, compassion on the son of her belly?"
And it doesn't say "Shall a father forget his son?"
And my teacher and rebbi, Shlomo of blessed memory [the Rashba], explained that this text which says "Shall a woman forget her suckling child?" comes to inform us of 2 things:
1) One is that there should be no doubt for Am Yisrael that they are the children of the Living God just as there should be no doubt for Reuven that he is the son of his mother...
2) ...And the second is that just as it's impossible for a mother to exchange her child for another, so it is impossible to exchange Yisrael for another nation.
Let's delve into the analogy of Hashem to a nursing mother.
A nursing mother literally cannot forget her suckling child, not only because of her natural love and concern for him, but also because her own body reminds her that her child needs to be fed. In fact, her body actually demands that she feed her child. ("More than the calf wants to suckle, the cow wants to nurse" - Pesachim 112a.)
It implies that not only does Hashem possess a Primal Need to nurture us, but that His Need to nurture us is stronger that our need to receive sustenance from Him -- which is an astounding statement because technically, Hashem has no needs!
But obviously, Hashem sent this nevuah to Yeshayahu so that we would understand in our own terms Hashem's Great Attachment to us.
It's mind-boggling, if you think it over. In fact, I can't quite get my brain around the concept.
But in short: God not only loves us, but He would never & will never give us up or exchange us NO MATTER WHAT.
And that's a pretty amazing thing.