Swollen Taste Buds And Swollen Throat, All Allergy Tests Negative. Any Thoughts ?

Hello, I have had swollen taste buds and swollen throat (on the inside) since March. I have had several episodes of what I thought was a severe allergic reaction (anaphylaxis shock). Went to see ENT and an Allergy & Immunology doctor. All allergy tests, skin & blood came back negative, and a few tests for some more serious cancers came back negative too. There doesn't seem to be any trigger. I do not smoke, I do not drink, my diet is limited to organic green drinks of kale, spinach, banana and blueberries. I do eat organic brown rice and sometimes chicken or steak. I do drink water all the time. My throat & tongue are not sore - just swollen, making it difficult to swallow sometimes. My family doc just ran a CBC and is also checking to see if I have a Vit B12 deficiency. There is sometimes a sour taste in my mouth, so I was wondering if it may be acid reflux - although I don't have heartburn. Sometimes when I bend to pick something up, I think I might experience gerd. This has been scary, and I never leave home without my Epipen - which I have not had to use (yet). I appreciate your thoughts and thank you for taking the time to try to help. AAAA