Hello, I am happy to give you some suggestions. You may experience a few days of discomfort after an injection. Anesthetic liquid can get into a blood vessel and cause swelling or a hematoma that will take time to dissipate. It is common for the side of your tongue to get numb when given lower anesthesia. You may have bitten your tongue and this may cause some discomfort on the side of the tongue. Headaches raise the concern of your bite. Do you feel like you bite the same as before you had your dental work completed? Sometimes you need to revisit the dentist for a bite adjustment and smooth a new filling. You may also experience some soreness from holding your mouth open for a long period of time. Please take some pain medication and anti-inflammatory medication. This would be Acetaminophen and ibuprofen. I Would need more information on the dental procedures that you completed to give you a more detailed opinion. If your gums are sore, consider rinsing with warm salt water and continue good oral hygiene. I hope this advice begins to help you feel better soon. I am sorry to hear that you are having discomfort. I hope my advice is helpful.