I taste something like blood in the back of my mouth and my throat is sore. i had a fever yesterday. what could the problem be? how can i relieve it?

Infection: You could have a simple thraot infection/pharyngitis. Take some Ibuprofen and/or chloraseptic throat spray for the soreness, increase your fluids and rest your throat/voice. If your fever returns, your soreness does not go away in the next day or two and or your symptoms worsen, than see a dr. As it may be bacterial and you would need an antibiotic. Get well soon!