T C Smout’s History of the Scottish People : https://www.amazon.com/History-Scottish-People-1560-1830/dp/0006860273
England started a trade war with the intent to crush the Scottish economy, that's why Scotland was forced to sign it, their supposed partner was actively trying to destroy their country and short of an all out war which Scotland would inevitably lose it was the only way to prevent swathes of the country being destroyed.
On top of that a large number of people were bribed for their votes by the English Government, 'bought and sold for English gold' as Rabbie Burns put it.
This BBC briefing touches on most aspects of it all including the English embargo against Scotland, what English spies in Scotland reported and general public opinion.
English spies in Scotland were perfectly clear about the situation when reporting back, Daniel Defoe said "A Scots rabble is the worst of its kind," he reported, "for every Scot in favour there is 99 against".
There were riots throughout the country following the Act of Union and they had to declare martial law throughout Scotland as the Articles of Union were publicly lit on fire, some of which is touched on here.
Sir John Clerk of Penicuik, an ardent pro-unionist and Union negotiator, observed that the treaty was `contrary to the inclinations of at least three-fourths of the Kingdom'.
The bizarre Unionist narrative of a poor, bereft, Scotland where everyone was desperate to join gracious and generous England that's been pushed since the previous Independence Referendum is absolutely bizarre and doesn't even stand up to even basic scrutiny.
If you want a more in depth read I'm afraid you'll have to get diving into some books, I can recommend T.C. Smouts book A History of the Scottish People, 1560-1830 for a more general (but very dry) view of everything leading up to it or The Union: England, Scotland and the Treaty of 1707 by Michael Fry was pretty decent and focuses specifically on the Act of Union itself, Independence or Union: Scotland's Past and Scotland's Present by Tom Devine is a more recent one that's meant to be pretty good but I haven't personally got round to reading that yet but it again focuses more specifically on the concept and implementation of the Union.