Knee had some fluid drained+cortisone shot 1.5 weeks ago. still painful and swelling is the same as when i left. why? what + can anything be done?

Swollen & pain knee: The high severity of your symptoms may explain why you haven't responded well to this round of treatment. I hate to think the doc missed the trouble spot with the cortisone injection, but you really need more care. Understanding what's causing the problem in the first place may better help your treatment. For example were you checked for Lyme? There are more aggressive treatments out there BTW.