<human>: Summarize the given text in a few sentences.

The back story: I graduated high school in 2005. I was always really into science and mathematics in high school,  and was urged by my parents and counselors to pursue an engineering degree. I took their advice, and that fall I started classes at a small, nearby, well-respected engineering school. From the first week, I should have realized that the school I picked and the major I picked were completely wrong for me; I hated the campus, couldn't stand the courses, and had a very hard time getting to know anyone on campus.  I started drinking a lot, and spent the vast majority of my time in my dorm room, skipping class and watching movies. I failed the majority of my classes my freshman year, but rather than taking a step back and changing schools, or majors, or taking some time off, I kept this up for another four semesters. I passed barely enough of my classes to avoid getting kicked out. I finally decided to just stop going after the Spring 2008 semester, and haven't gone back since. In the meantime, I've landed a job working retail, and I've kind of decided I don't want to do that for the rest of my life. 

That being said, I've decided I want to go back to school. I want to major in something science-related; either biology or chemistry. My questions are these: Is it realistic to think I can go back and finish a degree? If so, how bad did I mess up my chances of getting into grad school afterwards, if I decide to do that? Am I less likely to find a job graduating at 27 instead of 22? If I start back at a community college, would it bode poorly for future job opportunities? How do I avoid getting into the same rut the way I did the first time? And my biggest concern; is it worth trying higher education again? Or should I come to terms with the fact that I'm a college dropout and try to figure something else out?

Sorry for the wall-o'-text.
<bot>: I screwed up college the first time I tried, it's been two years, and I want to go back and get a science degree. Advice?