Every job worth having expects people to have a completed high school degree or better (queue the edge case anecdata). Dropping out now because of this job is highly risky.
Your next job would have to not care that you didn't graduate from high school (you will be 20 at that point)...most jobs who see a 20 year old that didn't complete high school only see a 'loser' whether that moniker is earned or not, for the hiring process, perception is reality.
I've been in a similar situation as well (got a Jr. SysAdmin job at 17, promoted to plain at 18, but had to split it between high school hours and later working on my 4-yr degree at college) thus, I understand your point of view.
The feelings of being held back by school are very real. They are not fun to experience. You are almost certainly robbing your older self down the road in lost job opportunities and more if you don't get that HS degree. Don't do it! Your 25+ year old self will thank you for making the painful, sucks to do, mature decision.
He got pretty good in a certain niche, and over time he built up legitimate experience - good enough to land senior developer roles in this market, and to be well-known to other developers in these circles.
The problem, for him, came when he decided that he wanted to try something new. Suddenly, his 7-8 years of real-world experience didn't matter for much, and he was struggling to get roles ahead of fresh graduates, because he didn't have a degree, but mostly because his experience was around this one language and one CMS. He'd hit a ceiling in this role, and couldn't really find a way out.
He's earned some solid money, but since leaving his current role he's struggled to find any meaningful work outside of what he's good at - WordPress builds, and now that he wants to do something different he's struggled to find work. He's still young enough to not be classed as a mature student, so he's going back to college and then onto uni part-time while he does contract work.
In your case it might make sense to take the job now instead of building up a ton of student debt to get that job in a few years time, but jobs don't last forever. This job might be amazing, but you might face redundancies, or find yourself isolated from your friends/peers, or find what my friend discovered - he doesn't really enjoy what he's doing.
One thing to check into - see what your state offers for early completion of school. In California, you can take the CHSPE - at least, that's what I did years ago. It's a simple test that, if passed, grants you the equivalent of a diploma. It's NOT a GED, it's an actual diploma and colleges don't look unfavorably upon it. Please look into it, ask your counselor at school.
Also, no matter how good current job is, it will end eventually. Without a degree you will have much harder time getting the next job, while fresh graduates with 0 experience will get picked over you.
You have a GED as an option. It is considered a high school equivalency. It's a single test that covers a battery of subjects. Pass it, and you're effectively done with high school.
I didn't finish high school in a traditional fashion. I ended up going into foster care as a teenager and bouncing from home to home before I aged out of the system. I had to go to work early.
Here's the kicker: since I went to college later and had some college experience, the GED is forgotten. No employer in my 20+ year career has ever asked about it. I eventually ended up getting a 4-year degree, and even though it took a long time for me to get to that point, it didn't hamper my career in the least.
I just finished a 4 year project freelancing as an automation coder for a telecom company. I did VERY well over those 4 years, in terms of income. Now I am an employee of that telecom.
"Success" for you will depend on how you define your goals. Your path there will very likely not be linear. Grit is required along the way, no matter what decisions you make.
I would recommend you take a long-term view, and not only think about the moment. That may very well mean taking the developer job. But if you do that, and curtail your formal education for now, remember you'll want to address that later. In my case, the experience FAR outweighed the formal education.
Feel free to email me, I'm happy to talk with you more about this.
"Hey, I dropped out of highschool to work as a developer. I'm really good at [language, framework], but my coworkers all have more formal CS skills. I'm thinking of going back to school, but it feels too late now. Any advice"
...Having said that, some dropouts do go on to do amazing things with their extra time. But think very carefully if you think that would be you.
I am glad I stuck with it. Not having a high school degree is frowned upon and it'll not be fun to explain that down the road. Society does not take kindly to people who don't finish high school. You are already going to have a harder time being a youngster in the industry, don't make it harder by not having a high school diploma.
It's going to suck. I know. But please, do us a favor and stick with it. If you want to talk, contact me by e-mail (see my profile).
In the mean time, maybe you could talk to your school. At my high school they were pretty appreciative and they let me do some software projects for the school. It was extra work for me, but at least it made me feel going to school was not a total waste of time.
Don't destroy your future to build some CRUDs with popular technologies (in the worst possible sense) every day and earn _peanuts_.
The wast majority of us hated it most of the times too, just go to school, do what you must and then start doing the stuff you care about once you get out. But get a degree, you'll need it.
High school just gives you more opportunities down the road, which is the most important thing at your age. Finally what happens if you lose the job? Then you would be left high & dry.
PS - At your age I spent most of my spare time programming on my own which gave me a lot of freedom to explore different things, not something you get in a job. [Edit - formatting]
In any case, I don't think formal education is useless, I'm just making the argument in extremis.
More than happy to hop on the phone to talk about my experience and introduce you to others who made similar life decisions that can talk about their experiences.