Why does it hurt to swallow....?

My throat hurts when i swallow my saliva and when i eat non-solid food like yougurt or drink water or juice. The only times it doesnt hurt are when i eat solids such as pizza. I checked the back of my throat and there is like a redish thing...like a scar or even a bump. I dont know! I have to hold my throat whenever i swallow my spit. Is \this normal?? How do i cure this?