Laryngopharyngeal Reflux. Laryngoscopy?

Every time I been to ENT he said Sinusitis and give medication my condition got worse...it's been three month... Now I have pain in my throat... can't breath ,water in mouth...ulcers come on toungue frequently and itchy mouth due to acid . I can feel the sensation of reflux and watery acidic taste in my mouth... No doctors believe my symptoms every time they gave that  sinusitis medication and asked to take steam 4times...I have taken steam for 3month as well ,I can't shallow it hurts n ear pressure got worse... when I take Antacid ( Mucaine Gel) before 15min of food ...I feel relief and no ear pressure... But I want full treatment... I'm so much fed-up now... I want to being diagnosed by Tests ... What test should I go for? Is GI endoscopy can diagnose or I should go for laryngoscopy?