Should I take Amikacin injections for my UTI?

Hello doctor,

I am a 36 year old female. I am currently breast feeding. I am suffering from severe UTI since 20 days. My gynecologist suggested Ceftum, Citralka, and Urispas for three days. After taking the course I was fine for two days. But, after two days, the UTI symptoms came back, but not as severe as the first time. I continued taking the same medicines again for three days. Still, there was discomfort, though the severity had reduced. I got a urine test done and attached the results. My gynecologist then put me on Nitrofurantoin, three tablets per day for a week and from the second week, I was asked to reduce the tablet to two per day. I have taken a total eight tablets, but there is still a burning sensation while passing urine, especially at night. Is this medicine effective? Will my UTI be cured by this medicine? For how many more days will there be a discomfort? Do I have to try a different medicine? Also, my gynecologist told me that if this medicine does not work, I will need to take a five-day injection course of Amikacin 500. Should I go for it right away?