Tooth infection post Root C - Swelling/pain worse after 4th day on Clindamycin?

I have a strange situation -- Had root c on tooth 30 last Thursday which went fine, painful but fine. Dentist said next up is tooth 29, which needs a re-treatment and new filling. Last work didn't get all of the nerve and pulp removed. Apparently, I have extremely deep roots. So, I was first on penicillin/vicodin and as of Sunday, am now on 500 mg Clindamycin and vicodin, but the swelling has not gone down, nor the has the pain subsided. Both are worse. It is a holiday weekend, so I am trying to hold out until Tuesday, when the Dentist's office opens again. In the meantime, I am not sleeping, chugging pills plus ibuprofen, rinsing with salt-water, resting upright and applying ice packs (was told NO heat should be used). Does anyone have a similar experience? I just want to know when the Clindamycin will take affect -- feels like the swelling/pain are here to stay forever, or at least until I go in a get this other re-treatment done. Thank you.