sore white bump between gum and cheek

For a few days now, I have had this sore spot in my mouth between my gum and cheek.  I don't know how it originally got there,  i've been trying to keep it clean, but it isn't going away. Also, the area on my neck/under my chin directly underneath the spot in my mouth has become sore--do I have an infection?? I'm terrified of dentists and would like to avoid a visit if possible. Should i rinse my mouth with warm salt water? please help!

[Matthew Baron, D.M.D.]

This sounds like a trip to the dentist is in order.  It could be a number of possibities one of which is an infection.  It is better to get to the dentist to determine what is going on before it's too late to correct any problem.