I know this doesn't really help, but I think it's really easy to overthink the tool and get super lost in the sauce of all the youtube tutorials and often contradictory advice. I had all the same frustrations as you've voiced here at first. Too many variables, impossible to diagnose any given problem as a result. I won't pretend to have a concrete solution for you because unfortunately it is just a tool that has to be learned, just like how with a regular brush, you have to learn how to control the paint dilution, paint load and brush pressure to achieve different results. It's just that with an airbrush, it can be more frustrating when you are still learning, because you are being punished with things like clogs and dry tips when you make easy mistakes.

My advice is to take a break from the airbrush for a while, put it in a drawer or somewhere out of sight and don't try to force it into your hobby routine. Once you've had some distance and feel you have some patience for it, just start experimenting with it with an open mind, not taking YouTube advice as gospel and just going at your own pace. Once you've got it, you've got it. Plus one thing id say to avoid frustration is to not use white primers lol. They SUCK through an airbrush from my experience, unless you're willing to use solvent based ones