My answer will be slightly biased as I am a nurse, but I would definitely say continue with your nursing studies, as that would be most beneficial to you. There are several reasons why I believe a career as a nurse would be superior:
Firstly, nursing is a career path, whereas CMA is a technical job. As a nurse, you can continue your education and rise higher and higher depending on what you enjoy. You may find there are specialties you perform better in, or just plain like better. Although it is true that CMA's also work at all levels of healthcare, pediatrics, clinics, etc., you will find that becoming a nurse would expand these opportunities far more. To add, getting your degree, whether you start with your Associates or BSN, there will always be the opportunity to study further simply by taking that degree and going to the next level. In contrast, sticking with the CMA path, you would find yourself back in general studies before being able to finish your degree. To add, there are many specialties and sub-specialties that require further certification, which does not mean returning to college, rather taking an extra course. Scrub nursing is an example of this, as with IV therapy nurses, and so forth. Personally, I like to look at the long-run: healthcare is hard on the body and the mind, eventually we will find ourselves at the point of being fatigued, and if you already have your ADN/ASN, BSN, etc, you can use that to work as a manager or teacher, or even research, getting your body off the floor and stop working 12 hours on your feet all day.
On that note, nursing will provide you with substantially more earnings, ultimately enabling you for better, and possibly earlier, retirement. Of course we like to say, "We aren't in it for the money," and, "If all you care about is the money not the patients, you're in the wrong line of work," but we must also be realistic. If you plan on having a family, or maybe you already have one, you would be better able to support them off a nurse's wage than a CMA's. Even if you aren't interested in the family life, as a nurse earning more makes for your own lifestyle to be better.
My last point, which I feel is the most important, which is why I am putting it last, is that your scope of practice is far wider as a nurse. If you find yourself interested in all the infinite opportunities to care for patients, you will be able to work in it as a nurse. For example, surgery. Yes, CMA's can assist on minor procedures, but OR nurses are present for the biggies, in the fast-passed traumas, and the experimental procedures, for the hours- and sometimes day-long operations. They staff the OR with nurses who are expecting to work as long as the surgeon. That is just one example of how much broader your scope would be as a nurse. I mentioned earlier research. Nurses at all levels, yes including LPN's, are able to participate in research. Many medical articles are written by NP's and other advanced practice nurses. There is also the matter of working internationally. As a US RN, you would be able to work just about anywhere in the world; working with relief services, or simply wishing to explore another country and culture. Here is a fun article about that: https://scrubsmag.com/nursing-abroad-becoming-an-international-nurse/.
As always, it is 100% your decision of which you choose, but I hope I helped.