As a proponent of Home-education and a former classroom educator and advisor, I'll advisechime in on advising that switching now is probably not the time (sorry). Instead
Instead, I would focus on getting your GPA up and figuring out how to explain the earlier low GPA in an "exceptions" essay. Even if you started homeschooling now and got a 4.0 (With clear proof a 4.0 was appropriate), it would simply be averaged with earlier work anyway. Switching to You need four years worth of work in your transcript - even if part of it is homeschooling does not wipe the slate clean forwork, you still need the work.
Focus on over-coming the challenges you have faced in the past so that you can speak about how you over-came them and are a better student now in interviews and in a short-essay response to, "Is there anything else we should know about you when considering your application." Umm and get those applications started!!
Consider these alternativesalternative "compromises" with your current school:
Finally
I started my application process during my Junior year (in fact, that was when I took my SAT as well). I was applying for early admission, but your are behind on this count even when not applying for early admissions. If you don't jump on getting started very soon, you may miss your window and find yourself relegated to waiting another year, or starting at a college you don't feel is of the quality you would like anyway. Figuring out how to switch and get a home school education that meets your state's requirements as well as those of your desired secondary institution will be a lot of work and take a lot of time and sacrifice for you and your lead teaching parent. Getting all of that going while ALSO working through Admissions and then Financial Aid applications is likely going to take a lot of time too.