I have been diagnosed with gerd and currently taking meds but somehow i have this phlegm that is sitting in the back of my throat constantly. please advise i havent experienced this before. post nasal drip and gerd ?

LPR: Postnasal drip is a possibility, but you may be experiencing laryngopharangeal reflux which is more troublesome than GERD and doesn't respond to typical antigerd treatment. An Otolaryngologist could evaluate you and confirm a diagnosis of LPR. He/she could give you more information and advice.

GERD, LPR, TIF : Sounds like LPR. Consider seeing surgeon specializing in GERD procedure (surgeon). This is treatable. ENT can also evaluate with pH probe, but repair usually laparoscopic/endoscopic surgeon if you decide to fix the issue in procedural way. https://www.idealbodyinstitute.com/general/advanced-reflux-center/tif/