Molar extraction and dental bridge issue

I'm a 30F with back-to-back dental problems from old work. On one side, both molars 1 & 2 had root canals 5 years ago. Molar 1 failed and was extracted last week. On the other side, molar 1 was removed at age 16. A dental bridge was placed in 2012 by trimming two healthy adjacent teeth. It was fine for 15 years. After chewing on that side post-extraction, I got mild sensitivity and dull pain. X-ray showed no root issue except a lesion on the last abutment tooth. The dentist removed the bridge, waited 24 hours, then re-cemented it. He said if pain persists, RCT may be needed. Since re-cementing, I still have sensitivity, dull ache, and occasional jaw discomfort. For the new extraction gap, he suggested a dental implant in 3 weeks to prevent teeth shifting. But I’m scared due to recent issues. I may also need RCT + a new bridge on the other side. Feeling very anxious.