I think it's dangerous to ask total strangers whether or not you're "capable" of doing anything. I don't know you apart from your stats, and it's impossible to tell whether the problem was motivation and effort or straight up lack of intelligence. Hate to be harsh, but there it is.
First things first, what you did in high school matters almost none at all in med school apps. With a 1.4 GPA in high school, you're looking at a community college as opposed to a big time university. Start taking any classes you think would be fun at a community college. English, writing, algebra, and biology might be good starters. Take as many as you think you can handle at once, but not too many. From here on out, you need to be making A's and maybe a few B's, if you're serious about going to med school. From here on out, grades count a lot.
Whether you hold a job at the same time or not is up to you and depends on your situation. I don't know how loans work at a community college, but I'd hazard they work similarly to 4-year schools. Depending on your comfort level with debt, you could probably take out loans to cover all your education expenses and living expenses. Community colleges are usually less expensive than their 4-year counterparts, so that might help some. However, I know a good number of people who worked part or even full-time while attending community college and were able to cover the full tab and take on no debt.
After you do well in community college for 2 years, you should transfer to a good 4-year university. There, you can finish your bachelors degree and apply to medical school.
Throughout all this, routinely go talk to the career center counselor(s) your school has. He/she will be able to pick out good classes for you to attend and help steer you on the right path for your chosen job.
Finally, in terms of what job you want, all those require a BA, so your short-term path is largely similar for any of them. Get the BA (or BS) and work out what you want to do while you're doing it. Job shadowing is your friend.
Most important of all though, do well! If you have a GPA of less than 3.4, getting into med school becomes a lot harder and maybe impossible.
First off, I agree with GoodmanBrown's aspect on asking strangers on your abilities. Just remember that no matter how good or bad of a history you have, you can easily change it in either direction.
With that said, a Marine Corps commitment is only four years long. If you back out of that (for whatever reasons), compare that to a medical career, which often said to be a lifetime commitment. You have to be completely dedicated to at least 8 years of education followed by several more years of research depending on the specialty. All of this while maintaining a balance in all areas of your life to include finances and personal life.
By no means am I discouraging you to pursue medicine, but you have to personally KNOW if this is something you are willing to commit to. I didn't know that I was going to pursue medicine until after I had started a graduate program and was well into military and civilian careers, but I was committed to a long stretch of educational goals which pushed me to do my best at all times.
My HS GPA was 2.8 and I was even denied into a state school. I knew that I was going into the Corps either way as I've always had an interest in the military. My college career had a rocky start as well as it's hard to focus on school while maintaining military requirements and partying as a teenager. In the end, I've kept my focus and have turned things around for the better.
Regardless, you can be doing any of the occupations that you have listed and it would benefit you to complete an undergraduate degree. Pick up on some good study habits and look into some gainful experiences. Maybe then you'll find what YOU want to do, which is all that really matters.
Previous posters- I read his "capable" statement not asking us if he possessed the intelligence, but an awkward expression of "is this possible still, logistically, with my sordid academic past?" Just my interpretation, so I won't comment further.
OP: Your first and only goal should be getting into a college program.
After successfully completing your first year, gear up for pre-med.
There's absolutely nothing to lose by putting every ounce of focus into getting into a good college program. At the very least, you'll walk away 4 years later prepared for SOME career, or SOME future graduate program.
If you have any life experience beyond what you're illustrated for us, then you simply must make an eloquent appeal to the local colleges in your area, and get help doing it. Also, there's absolutely NOTHING wrong with doing community college and then transferring over to a state school or whatever for your pre-reqs. If I were to do it all over again, I'd have done community college to start from the start.
At the same time you get accepted to a community college, I would begin speaking with pre-med advisors at the colleges you hope to gain acceptance to, because their knowledge of you and your aims will prove to be helpful down the path. Don't be shy about communicating your goals, and demonstrating your convictions, but be certain that your convictions aren't false or misguided, or you'll be wasting your own time. Medicine is brutal in many respects, and you have to determine whether your ideal is compatible with the clinical reality.