There are lots of bits I can't make work, but the fourth and fifth haiku seem to point strongly to
Odin, from Norse mythology.
My marriage a curse
among polite company
she's actually great
Odin's wife is called Frigg, which sounds like a slightly-rude word in English (and one which is sometimes used as a partially-minced version of a much ruder word). The last line might reflect (1) the fact that Frigg is an important and powerful goddess or (2) the fact that her name means something like "beloved".
From your home to mine
there's a rainbow connection
where the rhyme doubles
A rainbow connection between (it seems) two worlds? That sounds an awful lot like Bifröst, whose first two letters are suggestive of doubling. (The rhyme? Well, Robert Frost was a poet.)
I'm having enough trouble fitting any of the first three haiku to this that I suspect it's wrong, but maybe I'm missing some important things. Still, let me say what little I can about them. Credit to Angzuril for most of this (some bits I'd thought of but not clearly enough, and rejected).
When my life began
inside the superlative
city of angels
Presumably this is Asgard, though an aes isn't exactly an angel and a gard isn't exactly a city.
When the seed was placed
by a son of the entombed
a swine most untamed
Angzuril suggests awfully plausibly that this is a reference to Borr (which sounds kinda like "boar"), whose father entered the world by being liberated from a block of ice.
With my brothers' help
in the centre protected
I formed a new land
I suppose this must be Midgard, (mid=centre, gard=guard=protected) but "gard" doesn't really mean protected and even "guard" dooesn't (it means "protect" or "protector"). Was Midgard formed by Odin and his brothers? I am far from an expert on this stuff, but everything I've seen so far suggests that the main thing Odin and his brothers did together was to fight one another. ... Oh, but now that I look up Borr I see that the Voluspa says that Midgard was created by "his sons", so fair enough.
(After that I'm a bit more convinced than I was before.)