Your description has some parallels to my experience with ABPA, although mine is related to having childhood and chronic asthma so there is some difference, I also found amoxicillin (same dose as you) was the only antibiotic that was effective and knowing if and when to take it is always problematic. The main aim I have learnt, several lung infections later, is to treat lung infections early before any further bronchiectasis occurs. I am also taking anti fungal medication but I would love to stop. I was surprised none of the lung specialists you saw recommended a broncoscophy. I would like to know which probiotic you take?