Hello visit  if infection  is severe tooth feels like loosen. No need to worry .after clinical  examination suggest you the best. Xray required

If the tooth is in the corner of the mouth, it may be a wisdom tooth that is giving you discomfort. If it's wisdom tooth removal is a good option depending on the position of the tooth. If it's not a wisdom tooth, it may be a decayed tooth which got Infected. When there is infection or swelling u may find teeth is slightly shaking but as the root canal treatment is done tooth will be stabilize.

Nothing to woreey.fistly u start with three day antibiotic course and then ask ur dentist to take ur x ray and thqt tooth will surely go for rct. Once the rct is done u 2ill be relieved drom pain

Usually pain is because of a decayed tooth. The nerves inside the tooth must have been affected by the decay. You need to visit the dentist to take an x Ray. If the decay is involving the nerve, you may need a root canal treatment. Please do not delay the treatment as it may get worse and develop into a swelling Regards