HI and welcome to the GERD forum.
It is possible that what u r dealing with is gerd.....it is also possible that the time u were involved with the purging that it could be the reason for ur issues now.
When u vomit, it brings up acids from ur stomach....these acids can do damage to the LES and the UES.....which in turn can cause reflux and heartburn.
I would suggest u see a GI dr and make sure u tell him about ur bulimia.....
There r meds to help repair damage, but u have to follow all instructions from the dr.