I suffer from pain in several locations that is considered chronic.
My mouth has always had bad/severe pain. Most of my teeth are bonded/replaced and I still have issues. My brother when he was alive had it as does my father. Super acidic saliva in the genes.
Last year I fell off scaffolds and compressed my spine after landing flat footed in addition giving my extreme back pain.
I can tell you this, it is true when you live in pain sucide crosses your mind as well as depression. For people who don't have chronic pain it is very hard for them to comprehend that the pain is so severe and constant and life interupting that they don't understand why you would be so unhappy with life to be depressed and even think such things.
You need to talk to your doctor about it and if he brushes you off, another doctor. Contact a pain treatment center as well. If the medicines he gave you are not working tell him, if he brushes you off about it again a new doctor.
Contact a support group preferrably locally. They will help give you the strength to calm the depression.
Severe pain is no joke and does exists. Resort to heavy pain killer use as a last resort. They will relieve the pain, but in the end you are far worse off from them as you may have to take them a very long time.