Help gum and ulcer pain HELP!!?

ok so on one side of my mouth a new tooth is coming through and theres a big red lump on top and just poping ou the lumb is a bit of white not the tooth because the tooth is mostly through i think its an ulcer and its so painfu!! i cant even close my mouth properly but its the same on the other side but on the other side theres no ulcer so theres no pain its killing me help what should i do. thank you