Charity for past doubtful earnings

I worked at Burger King as a student and earned a salary for my work there, which I have already spent on rent and food in Germany. At that time, I did not know that selling non-halal meat is not allowed, even to non-Muslims. Burger King also sells halal items, and even in the burgers, some parts are halal, such as the bun, salad, and cheese, while the meat is the non-halal part. I sometimes worked as a cashier and sometimes in the kitchen. I never sold alcoholic drinks. I thought this work was permissible, so I did not think I was doing anything wrong. Now I have learned that this type of work may not be allowed, and I am worried about the money I earned. I am now working in a halal job. Do I have to give sadaqah from my current halal income to make up for the haram portion of my previous income? Note: I follow Hanfi school of thought.