Aching tooth after root canal

I had a root canal 10 months ago on my front tooth due to a severe abscess. For months following, the tooth continued to pain somewhat and occasionally moderately. The discomfort comes and goes. When I exercise, it hurts the worst. Sometimes, but not always, when eating. I don’t have any discomfort on some days. Strangely enough, it occasionally feels like it’s the neighboring tooth.