As a practical matter, you've left it too late. It's difficult to recover from a wasted high school experience - especially if you didn't take and do well in the crucial math and science courses.
A professional career as an astronomer (researcher, professor, etc) is probably out of reach. Even if you got into a respectable university with your background, you're looking at 4+2+2=9 or more years of heavy math-intensive study, only the last 2-4 have anything to do with astronomy. Real astronomers are often advised not to take undergraduate astronomy survey courses ("Astronomy for Artists") during thir undergraduate studies. They spend their time taking math and physics and chemistry. Even if you do slog through eight or nine years of hard study to get a PhD, you'll find a lot of competition for a job. Many very good astronomy PhD grads can't find work as research astronomers. You'll see them teaching in Community Colleges or running planetariums (and pushing aside perfectly good MS in astronmy grads to do so).
However, all is not lost. You could work as a technician or as a supporting technologist in an astronomy research facility. I'd advise you to get a BSET (Bachelor of Science in Engineering Technology) degree. Make sure it is TAC/ABET-accredited. (The NAIT-accredited BSIT may also be a reasonable alternative). The BSET degree is about half-way between a technician diploma and an engineering degree, with some of the calculus taken out but more of the "practical" lab work added. The BSEET - Electronics Technology - might be best, such as the BSEET offered by many DeVry Institute campuses. Or maybe a BSMET - Mechanical Technology - might suit your interests better. Some schools such as the excellent Oregon Institute of Technology offer a BSET in Optical Technology.