Swollen and difficulty in eating are signs of infection. Broken tooth may be due to advanced stage of decay. Foul taste may be due to pus draining in your mouth as the swelling is actually pooled up pus due to infection.
Next Steps
Visit a dentist, get it diagnosed and treated. Mostly RCT can save your tooth but the amount of tooth destruction will determine the line of treatment.
Health Tips
Delaying treatment can lead to spread of infection so do not neglect it and get it treated asap.