so here my monthly salary is about 3,500 Cuban pesos, which is equivalent to 12 dollars approximately,
Seems like you miss calculate the conversion of Cuban Peso to USD, according to google, 3500 is not $12, its around $146,
I work as a doctor or I used to,
Eventho I still think that salary is still quite low for a doctor, but $146 would still be enough to survive, but $12 is just not humane. Because you already has experience as doctor, I think the best option could be pursue your career as doctor, and save some money to get better degree and certification as medical specialist. Since you ask this question this forum so I assume you already know about crypto and Bitcoin, you could spare some of your salary to buy Bitcoin.