As someone who has been in your shoes (graduated college with a sub-3.0 GPA)... I can relate. I was told by everyone that I'd never get into med school, and honestly, I spent way too much energy worrying about it. The best advice I can give is that if medicine is your true passion, don't worry about the past, don't get bogged down in the negativity, and just focus on re-taking those C, D, F, and W courses. I completed both a post-bac and a master's, so below I'll provide you with my thoughts on each for your situation.
POST-BAC
Contrary to popular belief, post-bacs can be affordable if you independently complete classes piecemeal through a major university's extension school or through a local state school (in other words, NOT through one of those structured full-time programs). My most recent part-time post-bac stint at a top school cost $1250-$2500 per semester (including books), which is manageable with a part-time job. From experience, I found that it's best to start off taking no more than 2 classes your first semester (if you're also working), then bump it up to 3 the following semester if you are happy with your work-academic balance. If you're also studying for the MCAT, I wouldn't take more than 1-2 classes while working part-time, and those classes should be in MCAT-relevent areas.
The downside of doing it piecemeal is that you will have to be very self-motivated (but it's something med students need anyway), you may not have any of those 'feeder school' perks that the full-time candidates will, and it will take A LOT longer. For me, the piecemeal post-bac was worth it because I couldn't afford attending full-time AND it allowed me to concomitantly gain incredible work/life experience that really opened doors later on in my career. So even if you do a 'cheaper' unstructured post-bac like I did, it will nevertheless be counted towards your pre-med GPA, and it can lead to some pretty incredible places.
So in short... My biased opinion is: if you really want to go to med school and are short on cash, do an unstructured post-bac to boost that GPA and work experience. 
MASTER'S DEGREE
Beware. Unless it's a special master's program (which is similar to a full-time post-bac in terms of price), or a very science-heavy master's, few medical schools will be impressed with a 4.0 Master's GPA (only one of my MPH classes contributed to my pre-med GPA). Master's programs are extremely expensive (mine would've cost $130,000 without scholarships!) and provide very little pay increase considering their hefty price tags. Large scholarships for Master's are few and far-between, so unless you're already a very unique applicant, you will need to take some time to really bolster your resume to be eligible for an 'almost' full-ride or a full-ride (and even then, you have to be very proactive about finding money).
So if you do go the non-SMP/science-heavy Master's route, do it because you want to incorporate that degree in your future career as it won't boost your pre-med GPA as much as a post-bac will, and it will be VERY expensive if you do not put yourself in a favorable position to earn scholarships. About 20 of my classmates in my MPH program paid full price to attend for the sole purpose of gaining admission into med school, and ultimately, only 2 of them were admitted. As a result, most of them ended up with six-figures of debt, no med school acceptance, and no lifelong interest in their master's degree... Not good.
Moral of the story: aside from the exceptions noted above, I highly recommend AGAINST pursuing a master's as a means to gain admission into medical school. Get a master's if you 1.) can afford it either through scholarships or independent wealth and 2.) if you truly believe you will gain value from that degree regardless of whether or not you'll become a physician.
Hope some of this advice about the two academic options were helpful. While I LOVED my Master's program, I found the post-bac to be most beneficial in terms of med school admissions and it's what I'd recommend for you. In short, if you want to go to med school, you CAN and WILL do it if you work hard on grade replacements, gain more life experience, and submit a strong/cohesive application early in the cycle. With discipline, perseverance, and time-management you CAN reach your dreams. Good luck.
