Breastfeeding issue

[Kittycatmeow]

Hi, new to mumsnet. I'd appreciate any help or advice or insight.

My baby is now 7 weeks old. We had a really tough start with breastfeeding, turns out he had a tongue tie which took over 3 weeks to get diagnosed and sorted. He took really well to it once it was sorted and has been exclusively breastfeeding since. Before it got sorted I was expressing and bottle feeding him my milk. My right breast was always a bit of a slacker compared to the left, it would usually produce about half as much. However once breastfeeding this didn't seem to be a problem. Recently though baby has started to get really fussy on the right breast. This morning he wouldn't latch properly and kept pulling his head away (whilst attached!) and whinging/crying. I took him off and put him on the left breast and he latched properly straight away with no problems. The last couple of nights I've pumped, the right breast has produced 4 times less than left! I don't know what is going on but I'm really worried that I'm not going to be able to feed off of that breast anymore.
If anyone has any thoughts or suggestions it would be greatly appreciated.