You've got the most important part right there: drive. Having this will make even the grossest amateurs into professionals, and lack of it will grind the greatest natural talents down to the point where they throw away their pencils and styluses. This is what happened to me.
The next thing you need is patience. You won't be pulling in enough Patreon and commission dollars to quit your day job until you put in the time and effort to get good.
Next step, just draw. Draw what you see, draw what you feel, draw what you think...just fucking DRAW. Once you have a baseline, once you have some graphite on your hands, then you can start refining it with art books and references. I personally recommend Burne Hogarth "Dynamic Figure Drawing" as a starting point, especially if you do want to eventually do lewds, since knowing how to construct anatomy in your head and make it do what you want is WAY cheaper and more flexible than models or reference art (although a good refs folder is invaluable).
Learn to separate the legit criticisms from the trolling, because you WILL encounter more assholes than admirers. Again, this is where the "Drive" and "patience" aspects come in...remember that you are always improving, every time you make a new line, and it makes this easier. You don't have to post every one of them online, though...that's another lesson I wish I'd known earlier.
And, I know it's cliche' and trite and stupid-sounding, but ti's important: enjoy what you're doing. If drawing becomes a chore, that will kill your drive faster than anything. Just relax and let it become as normal for you to do as talking, and that'll carry you through the dark times, which WILL be there.
OK, end blogpost, I know...
TL,DR: go back and read it, you lazy fuck.