Its actually not uncommon to experience weakness, tiredness, confusion, and headaches after completing certain types of malaria treatment. Some medications can stay in your system for a while even after you've finished the course. In fact, these symptoms could be due to the medication's side effects or possibly even a lingering infection. I would recommend reaching out to your physician to discuss your symptoms. They may want to run some tests to check your blood count and see if there are any other underlying issues that need addressing. In the meantime, make sure you're staying hydrated and getting plenty of rest.