Cortico-steroids can be extremely anxiety provoking, as they are mimicking the cortisol from our adrenal glands that are thought to be the trigger for severe anxiety in anxiety sufferers. Bad taste has nothing to do with bad effects, some drugs just taste bad. I don't know about the reflux but the anxiety is a common reaction.
Prednisone can work wonders. BUT, for some can create bad reactions. Me. I had the worst case of poison ivy and it was my first time having it as an adult so didn't know and scratched and spread it everywhere. I just want to tell you I have never been more miserable. Doctor prescribed a high dose or prednisone (bolus dose) and then lower dose after that initial start. I hallucinated. Yep, thought I saw snakes coming out of my ceiling fan and panicked and got my mom to my house in the middle of the night. Years later, my son also had an allergic reaction to something plant based we think and had a major rash. He was prescribed prednisone. My sweet son had what appeared to be tourettes from it. He has mild tics due to anxiety but hadn't really had too much at that time yet. But this was scary. He would jerk and yell things! Doctor was like "stop the prednisone asap". That was the experience of myself and child on prednisone. So, if you are having increased anxiety and depression and mood changes, yes. I think it could be related to prednisone.
It takes about 16-22 hours for Prednisone to leave your body so don't be anxious about the drug, I was let down by a lot of doctors over the years just for a piece of mind just for one word from the doctor, and a good doctor will never let you suffer from anxiety about your well being and your health. Since 1995 I developed this anxiety about allergies I was started having, went to the doctors office was told it was allergies and was sent on my way with "Go to Walmart and buy Sudafed" and nothing else. The doctor did not take his time to explain what allergies were or how they effect your body, he just let me walk out of the office all anxious and worried , and when that happened I developed anxiety was stressed out and all the works because Sudafed didn't work it just dried my runny nose, suffered from being anxious for several years and I still do , till this day my stress and anxiety kick in out of nowhere, I am used to them I just live with them, over the years since then every year I have allergies. The doctor needs to be trained in recognizing a person that is susceptible to being a candidate for becoming anxious and explain their condition to assure that it is more or less not life threatening. Due to this anxiety and stress I suffered with Premature Ventricular Contractions which started in 2007 and lasted until 2017 thanks to self care , visited multiple doctors heart specialists did all the EKG's multiple times ECG , was told nothing is wrong it is all "benign" , in a mean time when my heart was feeling like it was stopping and starting thru out the day and night my anxiety was shooting through the roof doctors , specialists had no clue what to do about them. They would prescribe Beta Blockers to cure anxiety. I healed my PVC's over the course of 2 years and now I am virtually PVC free. Due to allergies over the years I have developed Eustachian Tube dysfunction which causes me ear ache and pain fell like I am on the boat that is slightly rocking all the time kind of off balance feeling, my body has gotten used to it , it does flare up here and there and when it does it is debilitating so recently went to see a doctor and he pretty much said there is not much they can do about it and prescribed Prednisone for 5 days and Singular for as long as it takes to see if it might help , I will give it a try and see what it does but I feel like I am on my own on this one too. For your anxiety about Prednisone don't worry it is going to go out of your body as for your anxiety see a Psychiatrist they will ease up your anxiety and worry. You control the worry yourself concentrate on your body, Don't let your anxiety deprive you out of your life happiness like it did me.