Both, actually. I loved it when Andy Murray won Wimbledon, I genuinely viewed that as a British win. I'm no fan of curling but was pleased as punch when a team selected almost exclusively from the western isles (IIRC) won the gold at the winter Olympics. I take as much pleasure when Rory McIlroy wins at golf (though that's not such a common occurrence these days) as when Tommy Fleetwood does. So many of the great achievements of the Victorian age were, as you know, achieved by scots especially in fields like engineering and medicine, and when I think about them I don't shrug and think 'Scottish, nothing to do with me', I think 'this is what our country has achieved, and it's fucking brilliant.' I think the Bell Rock lighthouse and the Bristol suspension bridge are engineering miracles alike, and I don't distinguish between them on the grounds one was designed by an Englishman, the other by a scot.
In similar vein, I'm always hugely proud of great feats achieved by Mancunians, but that doesn't stop me being proud of great feats achieved by English men and women from Sheffield or Bristol or Plymouth, or of Britons from Cardiff or Belfast or Edinburgh.
As to the current situation, I think I will restrict myself to saying that however you define your nationality, this is not our nation's finest hour.