I was recently diagnosed with postcholecystectomy syndrome. What should I do now?

Vague diagnosis. The loss of the gallbladder should not lead to any long term sequelae. The gall bladder is a non vital storage vessel only, and not particularly important in a first world country. You still have all your bile, so there's no significant GI disruption. If you have urgency, try Imodium (loperamide) AD as needed. Eat a balanced diet, add yogurt, and good hydration. Good luck.
This condition. can sometimes be a difficult problem to treat. If your doctors are certain that there are no stones in the common duct, they will probably treat you with medications. If meds do not relieve your symptoms significantly, some gi specialists will recommend endoscopic sphincterotomy depending on test findings. Consult with your gi specialist for specific recommendations.