For 2 days feels like there's a lump in throat & it burns. Burping & sometime bitter taste in mouth. Antacids don't help-can acid reflux last this long?

Possible LERD. Exposure of the vocal cords to stomach acid & pepsin will result in inflammation of the vocal cords (as is also often seen with acid regurgitation) = lerd. Acute laryngitis may result, but watch out for chronic hoarseness, throat clearing, airway spasms, cough, bronchitis, an asthma-type presentation, & even a higher risk of throat cancer. May however not be reflux so please get yourself checked.