Please help with 15month old's problem

Hi,
I need some advice with my 15month old. lately he has been not been
wanting to bf and when he latches on it is a shallow like latch. he has
always been breastfed and we never had any problems. I have tried
making him open his mouth wide and say AHHh before he latches on but
his latch is still weak.

he is getting his molars and I am wondering if this has something to do
with his reluctance to breastfeed. until about 3 weeks age he was
bfeeding 5-6 times a day and would have got at least50% of calories
from bm. I don't want to wean and am keen to b/feed for as long as he
needs to.

yesterday morning he really wanted to b'feed in the morning and it wass
the time I had the most milk but he tried to b'feed but was not very
successful and started to cry abd cry. i used a breast pump and know
that I still have milk but I know my supply has gone down a lot because
of my DS refusal to bf .

What can I do? did anyone else hve problems with bfeeding a toddler who
was teething?