If I want to become a professor for either Biology or Psychology, should i be doing what I'm doing?

There are two primary types of professors - research professors (most coveted) and teaching professors -- so your path will depend on where your interests most lie. There are also two types of universities - research-oriented universities and teaching-oriented universities. Both types have research and teaching components, but the type of university will influence what degree of priority is.

For becoming a research professor, the most common path is getting a PhD (with or without a Masters in between -some PhD programs will give you a Masters automatically on the way towards a PhD) followed by at least one post-doctoral fellowship. During this time you'll be writing papers as well as learning how to write grants to obtain your own funding, both of which are important for applying to professorships in your field and overall being successful, particularly at universities that are very research-oriented. If you choose to work in your field first to see whether a professorship is what you want, you could get a masters or go straight into working in the field, but then you'd still need to obtain a PhD/post-doc to start the pathway towards professorship.

If teaching is what you're really interested in, having a PhD will qualify you to teach at the college level. As a grad student, there are several opportunities to be teaching undergrads, so there's no real need to get a separate teaching degree (e.g. Masters in Education, which many high school teachers get) if you've gone through the PhD already. Teaching universities will still look at your research productivity as a graduate student, but more weight will be placed on your teaching experience. Unlike research-oriented roles, professorships that are primarily teaching-oriented may or may not place you on a track towards tenureship (i.e. job security), which is ultimately what you'd like to achieve. This is very university dependent, so it would be good to revisit your career goals once you get to that stage.

Teaching high school and teaching college are two completely different things. To teach grades K-12 you need to have a teaching certificate. You can teach K-12 with only a 4 year degree though most have a masters. You will likely never get a job in either of these two fields in college without a doctorate degree. I have a Psy.D. degree and have found that most colleges and universities prefer the Ph.D. because it is research based and colleges and universities stress theory. It is faster to get certified to teach K-12 but you have to like working with this population. The value of the doctorate is that it opens other doors if you find you don't like teaching.

I am in 100 percent agreement with the two previous answers to your question. I would like to add that most states require a masters degree in education for full certification as a teacher after the second or third year in the teaching position Teaching high school students is VERY different from teaching college-aged, young adults and non-traditional students (those returning to school later in adulthood).

Some smaller colleges and universities will hire faculty as "instructors" (not professors) with just a masters degree in the discipline. The chances of landing a full time job with just a masters degree is better at Community Colleges where the emphasis is on teaching and not research. Landing a full time, permanent faculty position at a college or university is becoming more and more difficult, unfortunately. Nationally, 70 percent of faculty are contingent faculty (teaching part-time without benefits or with one or two year contracts). I hope this last statement doesn't discourage you - it is important for you to know what the job situation is like, currently. in colleges/universities.

Lastly, follow your dreams. Good luck!!