I noticed tonight that my baby has been having bad reflux after every feeding (breastfed) so tonight…

I noticed tonight that my baby has been having bad reflux after every feeding (breastfed) so tonight I decided to pump to see if maybe something is off. Well the whole time in each breast I've ONLY gotten foremilk. The really thin watery bluish milk.... I'm thinking that's the cause of her reflux because I started giving her formula as a supplement (doctor and lactation recommended due to latch issues) when she drinks the formula she doesn't get it. She sleeps better, and isn't fussy. What can I do to lessen the foremilk and produce my hind milk? I just learned tonight that after almost two hours of pumping I'm only producing the foremilk.

Note: I now am able to get her to latch perfectly but now it's the issue of getting my hind milk supply up. I don't want to have to keep supplementing with formula or stop breastfeeding all together.