This is a perfect example of a commonly misconsepted thing about depression: You are always sad and lonely. That is 100% not true. While you do feel sad and lonely most of the time. You are always in a neutral mood during the times you are not.
Porto looks beautiful! We're in Lisbon for a while, and it looks very much the same. We love it here, and you're right, the weather has been amazing compared to Canadian winter. Cheers :)