I I've Noticed Something White And Very Large On My

I I've noticed something white and very large on my tongue, but all the way back in my throat where I can't reach. It's bothering me. I can't drink anything or eat anything or take medicine without it bothering me. It's giving me heart burn so bad and I've looked up tonsil stones and it doesn't look like those. What could it be? I've also noticed it looks like it has red "veins" in it. Should I be concerned?