Do I need antibiotics or not?

I came down with something last Wednesday night and it just attacked my nose with severe congestion, pain and pressure. Had sinus xray and my ent wanted me to go on antibiotics as a precaution. I was very weak on Friday and Saturday. I have not taken the antibiotics yet. Saturday night and Sunday and today my energy is back up but I am still severly congested and I woke up this morning with junk coming out of my chest. Seems like its moving down. Question..should I start the antibiotics now or wait a few more days ...its been 5 days now. Thanks for any suggestions. I have been trying to stay off the antibiotics this year. I am leaving for vacation this Friday morning and dont know what to do!