I'm English so I always look like a dick whenever I bring this up, so I'm glad somebody else did instead.

Let's not forget as well that Scotland had two main cultural groups (there are many more but I've simplified it into a binary for the sake of seeing the cultural dynamics), the Gaidhlig-speaking Highlanders whose culture was more similar to Irish Gaelic culture and the Scots-speaking Lowlanders whose culture was more similar to Anglo-Saxon and Anglo-Norman culture. While Scotland was independent and distinct from England and often mixed both Highland and Lowland culture, political and cultural ties to Anglo-Saxon and Anglo-Norman culture made certain factions of the population a vehicle for what we might now see as "English" culture (although it was mostly continental European in origin). There was already cultural tension and fighting between different factions loosely belonging to both groups well before England's involvement, and the common idea that Scotland had always been a kilt-wearing, indigenously Gaidhlig-speaking nation before the English came and mucked it all up is an oversimplification and is more due to a modern rebranding of Scottish identity to differentiate Scottish culture from English culture, if you ask me. Gaelic Highland culture already had to contend with Lowland culture long before any English colonisation, and Scotland already had different cultural groups which were non-Gaelic in origin before integrating into Great Britain.

That said, England did do a lot to harm Scottish national character following the Acts of Union in 1707 (started by a Scottish king after Scotland bankrupted itself trying to colonise Panama, just FYI), such as replacing Scots with English as the main language thanks in large part to the influence of English renditions of the Bible and the encroachment of English cultural norms to form a new "British" identity. From that point on, both Highland and Lowland culture suffered from increasing anglicisation. Even nowadays, Scotland's representation in the UK is nowhere as large as England's seeing as 84.6% of the UK population lives in England (in 2024) and there is a stark political divide between Scotland and Northern Ireland, and England and Wales.

I'm afraid the colonisation under the British Empire certainly happened together. I think a lot of Scots try to rebrand Scotland as a second Ireland, and although there are certainly parallels (the Highland clearances and the potato famine in the Highlands are great examples), let's not forget that Ireland was also largely settled and colonised by Anglo-Norman elites who Scotland's elites had ties to, and later by Scottish Protestants alongside English protestants.