Hey there! I graduated with my engineering degree in 2017 and applied this cycle. I have a few DO and MD acceptances so far (with a lower GPA than you) so it's definitely possible.
Does your GPA have an upward or downward trend? With a strong upward trend, I think a low GPA is less of a negative factor.
I don't think there is a structured postbacc program that will help you get everything done but I can give you my two cents based on the DIY program I used.
1. I would get some shadowing/clinical volunteering experiences ASAP. Not only will this help you build your application, it will also help you solidify why you want to become a physician. Personally, I got my EMT license and used it to volunteer in some free clinics. Not only did my clinical work help me build my application, it also was a refreshing reminder of why I wanted to be a physician when I was feeling especially bogged down in organic chemistry or MCAT studying. EMT is a great option because in most states it will allow you to work/volunteer in a wide variety of clinical settings. It also doesn't take long to obtain the cert; I got mine in 12 weeks. You can also look into medical assistant or CNA programs.
2. Finish up your prereqs. Every school is slightly different but it is a safe assumption that you will need one more biology class and an organic chemistry class with lab. I recommend taking biochemistry as well, especially before you take the MCAT.
3. It's definitely possible to do self-study for the MCAT. Other people may have different opinions but I don't think you need to take a class to prepare. I feel my engineering background prepared me well for the MCAT and I assume the same will be true for you. It's a problem-solving/critical thinking test, not a rote memorization/regurgitation test.
I realize this reply is very broad and possibly not all that helpful. If you have more specific questions, I am happy to answer them. Always excited to "meet" other engineers transitioning into medicine. 🙂