On my second prescription of Macrobid still feeling some symptoms would furadantin (nitrofurantoin) work instead?

SAme drug. Macrobid is (nitro)furantoin, avoid this if making you feel sicker. Call your pcp.
Same med. Macrobid and Furadantin are different brand names for the same generic medicine, nitrofurantoin. Whether it works or not often depends on culture results, which most doctors would have done before starting an antibiotic. Some don't tolerate this medication well. Please tell your doctor that you're still having difficulty, and follow his/her advice. Chronic infections can be difficult.