What Causes Constant Vomiting Feeling, Gas And Acid Reflux?

I constantly have a feeling of vomit in the back of my throat. I am very gassy and I have acid reflux bad at night. It has been so bad that I can not even sit up in a recliner and sleep. I have also noticed that if I wear tight jeans I have the feeling in my throat worse than if not having tight jeans on. I feel like I am backed up in a way. I do get somewhat relief but just briefly after I have a bowel movement. Any suggestions?