The land theft was fundamental to the famine.
Under the British rule, the Irish were not allowed to own land and had to rent it from a British landlord; more important still, the Irish were not allowed to rent more than a half-acre.
The only crop with a sufficient yield per acreage to feed yourself and have enough left over to pay rent off a half-acre of land, is the potato.
The potato blight hit the entirety of Europe, not just Ireland. Only Ireland suffered a famine. Because the British rule had reduced the options for the Irish to potatoes or starvation.
Yay Sandy news! And I hope your surgery will go well and that you'll receive fast.