Ladies any advice. ( kind of long )

So my DD has been the perfect baby we struggled with BF the first few weeks but she’s almost 7 weeks old and feeds sooo well now ! For the last week she’s been very fussy , coughing ( dry cough ) , sounds like she’s trying to hack something up and vomiting an excessive amount after EVERY feeding she also eats about every 2 1/2 hours when she eats from bottle ( what I’ve pumped) she will eat 3 oz an still be hungry so I started giving her 4 oz . If she pulls off my boob I try to burp her an put her down etc or bottle I try to give 3 oz an she screams an cries hysterically so I continue to feed her more and she’s content .. so I Took her to the pediatrician today for her vomiting and hacking doctor suggest reflux and over feeding ? She was born 6 lbs 5.1 oz left hospital at 6lbs 1.5 oz an today weighed in at 8 lbs 15 oz .. she’s gained almost 3 lbs in just 6 weeks . Do you guys think I’m over feeding her or any suggestions .