I have had alot of UTI'S in the last yr. I get one about every other month. I have had them my whole life.?

I hate haveing to spend the money for the drs visit and than the cost of the meds. I was put on Macrobid 100mg 1 time daily as a preventive. I am feeding my newborn son and CANN'T take it at all. I need a GOOD preventive THAT WORKS so I dont contract another one while I am off my meds. Thanks for ANY info ....