Well, first I think it would be hard to have an "acceptable" GPA if you're collecting Cs every semester...keep in mind right now almost 60% of people applying to medical school don't get in *anywhere*, so it's not really a process where you want to just aim for average.
But the broader problem, I'd say, is that you seem to have recognized the problem but aren't making much effort to respond and change. In the very least, that's not something you can get away with in medical school, where the main problem isn't so much difficulty but rather sheer volume of content. Also, your explanation for your grades would be a definite red flag for interviewers when they ask...and trust me, they'll ask.
The good news is you definitely have time to turn things around....or in the very least, reassess your priorities. You seem to know you need to be doing better but still can't quite get yourself to do it, which to me would suggest you're not entirely sold on your current career path. If that's not the case, that's great...so go study!