I mean if you could explain to your the interviewers and on the application about your parent's financial situation, I believe it's more than good enough an answer for moving back and taking classes at your local university, at least according to my school's pre-health advisor.
As for your extracurricular activities yea I guess it would suffer but I would think you could continue volunteering...that tradeoff for maybe lowered EC status for saving money at your local school...I don't know, must be up to you to decide I guess, as we don't know exactly how much your EC status suffers...