how you know if your breast got infection ?

My breast nipples are swollen , inside got black blood and there are white ulser near it area . Why ? Feel so hurt when touch it and give a breastfeed and when i pump today , blood came out too but a bit . I don't know if all this time is it the blood came out or not when i feed it but i try to pop it out nothing came out . I scare if i got any infection . Please help me . It almost 1 week already , i maybe will go to hospital this Friday . But i need to know if there any i can do to reduce the pain before i go to hospital for checkup .