Breast Pain – what if it’s not thrush?

I have been breastfeeding for 3 months now and my breast hurt since my baby was about 2 weeks old. I was given antibiotic when I gave birth to my baby due to complication (both injection and oral). My baby has thrush in his month and my breast start hurting from week 2 so I was treated with thrush medicine.
I’ve tried clotrimazole alone, clotrimazole and fluconazole (14days) together, and now on miconazole when all these time the baby has been on Nystatin.
All the treatment seems to ease the symptoms within 2-3 days after using them but then the pain come back. It hurt for a few days and the pain ease off for a few days and then come back. It has been like this for the last 10 weeks of treatment.
When I was treated with thrush medicine for about 8 weeks, I went to see another GP and want to have a second opinion. Since I was having all the above treatment for so long, he believed that my thrush was cured and the pain was related to something else and he subscriped me with antibiotic for a week. I showed my concern of using antibiotic as it was the cause of thrush but he reasure me that the one he gave me would not cause thrush. So I stopped the thrush treatment and took the antibiotic. However, once I stopped the thrush medicine and after the 1 week antibiotic treatment the pain intensify. So I went back to the GP and suggested it might still be thrush but he refused to accept that and asked me to take pain killer only!
I went to a 3rd GP and told her my situation and then she gave me thrush medicine again.
I’m a bit confuse and not sure if it is thrush or not…. If I apply the medicine consistanly, why the pain always ease off and then come back after 2-3 days? I didn’t have the very sharp deep pain anymore but have a medium depth and less sharp pain every now and then. On top, the nipple and aureola area become quite sensitive mainly after breastfeeding. It’s also sensitive to touch too so wearing clothes seem to make it worse! It also have a funny sensation (uncomfortable but not necessary hurtful) when milk let-down during those painful day. But feel less uncomfortable during let-down on those pain ease-off days.
Is it still thrush that course the pain? I wash my clothes every 3-4 days in the washing machine with the 90oC setting. Is it sufficient?
I start reducing breastfeeding and changing to bottle fed. If I stop breastfeeding totally, it should help to tackle the thrush (if it is!).
I have consulted the breast feeding specialist and she’s not 100% sure if it is thrush as it’s been treated with the thrush medicine for so long. But she’s sure that it is not Mastitis. She thought it may be due to narrow duct but it doesn’t fit all the symptoms!