Hi, I Got A Blister From Playing Tennis 2 Days

Hi,
I got a blister from playing tennis 2 days ago. I covered it in band-aids and kept playing. Today I played tennis again, and it hurt SO MUCH but I took through the pain! Today when I got home I noticed my blister popped and clear fluid came out. Later it turned purple!! My dad put sav on it but I have OCD so I'm obsessed with it and I'm really scared! Please help!