You might want to see an oral surgeon to make sure it's nothing of concern because the tip of your tongue should not have a bump on it in most cases. An oral surgeon would be able to rule out any type of mouth cancer. Likewise, any bump anywhere on your body should always be checked out by a doctor/dermatologist and biopsied if concerning or suspicious looking. It's probably nothing but better safe than sorry! Best wishes!
I know what you mean. They are very painful and annoying. My suggestion is to drink a lot of water and eat a lot of dull foods. The reason it's white and different from all the rest of the taste buds is because you ate something that irritated it.