"...but I have to ask: If the Bible says that "...a day with the Lord is as 1000 years, and 1000 years are as a day", then just how long was the creation week?"Since you asked about the Bible :
And God said, “Let there be light,” and there was light. 4 God saw that the light was good, and he separated the light from the darkness. 5 God called the light “day,” and the darkness he called “night.”
And there was evening, and there was morning—the first day.
6 And God said, “Let there be a vault between the waters to separate water from water.” 7 So God made the vault and separated the water under the vault from the water above it. And it was so. 8 God called the vault “sky.” And
there was evening, and there was morning—the second day.
9 And God said, “Let the water under the sky be gathered to one place, and let dry ground appear.” And it was so. 10 God called the dry ground “land,” and the gathered waters he called “seas.” And God saw that it was good.
11 Then God said, “Let the land produce vegetation: seed-bearing plants and trees on the land that bear fruit with seed in it, according to their various kinds.” And it was so. 12 The land produced vegetation: plants bearing seed according to their kinds and trees bearing fruit with seed in it according to their kinds. And God saw that it was good. 13
And there was evening, and there was morning—the third day.
14 And God said, “Let there be lights in the vault of the sky to separate the day from the night, and let them serve as signs to mark sacred times, and days and years, 15 and let them be lights in the vault of the sky to give light on the earth.” And it was so. 16 God made two great lights—the greater light to govern the day and the lesser light to govern the night. He also made the stars. 17 God set them in the vault of the sky to give light on the earth, 18 to govern the day and the night, and to separate light from darkness. And God saw that it was good. 19
And there was evening, and there was morning—the fourth day.
20 And God said, “Let the water teem with living creatures, and let birds fly above the earth across the vault of the sky.” 21 So God created the great creatures of the sea and every living thing with which the water teems and that moves about in it, according to their kinds, and every winged bird according to its kind. And God saw that it was good. 22 God blessed them and said, “Be fruitful and increase in number and fill the water in the seas, and let the birds increase on the earth
.” 23 And there was evening, and there was morning—the fifth day.Exodus 20:8 11 "
For in six days the Lord made the heavens and the earth, the sea, and all that is in them, but he rested on the seventh day."
I completely understand that this view is not common...... That the bible is clear as to what a day is.
Your quote from Psalm 90 v 4: "For a thousand years in Your sight Are like yesterday when it passes by, Or as a watch in the night." Has a pretty clear context about the Lord's Omnipresence rather than a contradiction with Genesis and Exodus and the creation narrative.
Only because you asked...
Edit:
If you are really interested in a creation view that is supported by real scientists, geologists, anthropologists etc. That is challenging but polite try this:
https://answersingenesis.org/ I follow them on Facebook and get little dabs of science/religion debate from the creation science perspective.
Also; I still dislike monkeys