It does look like a root stump in 48 region. Although it has to be clinically examined. But it does not look infected around the suspected area in the xray.The suspected root stump area may not be the cause of your pain. Your symptoms give an impression of bruxism/ myofacial pain, as your canine cusp tips are worn off as seen in the xray. There is widening of periodontal ligament surrounding the 47 and 45 region may be a cause for periodontitis or stress on the teeth. Only a clinical examination can be useful.
Next Steps
your description of symptoms require clinical examination. visit a dentist / periodontist to examine 47 and 45 region as there is widening of periodontal ligament surrounding the tooth. deep examination of the gums in 47 and 45 region required. also rule out bruxism / myofacial pain.
Health Tips
try warm salt water rinsing of mouth daily, also a water flosser can be useful to keep the interdental and gum areas clean .