The info in this thread might help. (But you don't have to stick things in your ears!!)
If you scroll down to my post, you might find it interesting.
Of course there are exceptions, but most people need a pretty highly developed right hand, with excellent finger independence and good control over dynamics and articulation, before starting to attempt it. It's an incredibly difficult technique and quite a few concert performers don't manage it very well.
However, I can see it might be possible to achieve by people who have not played very long, with an awful lot of dedication, as Dave says.
It's also the case that some people can do it much easier than others. Probably something to do with their physiology and / or mental attitude.
But, since you've been struggling for so long, beautiful as the tremolo is, would it not be a better use of your time to develop your guitar playing in other areas, for the time being?
“Do what you can, with what you have, where you are”. Theodore Roosevelt