I completed my first semester (only one not 2) with at 2.8 and graduated after 5 years with a 3.7
The extra time was because of a switch in majors, at the end of my fourth year I had a 3.5 or 3.6.
This kind of thing is totally doable you just have to bust your butt the rest of the time. I recommend keeping track of your grades by determining how many points you need for an A and keeping track by counting down rather than counting up and thinking about how many points you have left to earn. When each point is a loss not a gain you will get a better and much more stressful grade in a class.
Alternatively, reconsider a career in medicine. After 5 years of premed I'm starting to think that if I had to do it again I may have taken a different route, considering the lost earning years and high debt/taxes you wont make too much over your standard college grad who just goes straight to work and invests moderately well till your at the tail end of your career and the idea of helping people gets a little fuzzy.