Hey
@Psynaught
I highly recommend not using Fentanyl ever. It sounds like you have access to other, more reliable Opioids. Fentanyl will inevitably destroy your tolerance if you mess around with it. It will sneak up on you and once you're in it, it's extremely difficult to get out even relative to other Opioids. Think about that. You still are in a place where these other Opioids work for you, If you continue messing with Fentanyl, you'll quickly be at a point where only Fentanyl will work for you.
Yes, Opioids are effective medications for dealing with illnesses like the common cold, influenza and respiratory stuff especially i.e. Covid-19. Opioids in general relieve pain, mental and physical. In theory, taking an Opioid will make any person, in any situation feel "better". That's just what they do. It's why we all know and love them.
Most commonly used Opioids are powerful cough suppressants. Tuberculosis was a huge issue all the way up until antibiotics were introduced in the mid-20th century. People would basically cough up pieces of their lungs bit by bit as this disease progressed. Lung tissue would die and be coughed up. Also, Tuberculosis is spread through droplets from the lungs. This made Opioids very attractive treatment for the condition. It soothed their pain, helped them sleep and relieved their misery.
Until maybe ~25 years ago in the USA and ~10 years ago in Europe/Canada, cough medicines containing Codeine/Morphine etc. were common and available over the counter. Cough medicine might have Paracetamol, Codeine etc. They are actually very effective.
It's different for you when you have a tolerance to these things. However, I'm sure you'll feel better having taken an Opioid than not having taken one, but again. that's just how they work.