programming is easy
I would not also underestimate the amount of effort, study and frustration that effectively retraining from scratch involves. You will need, at a minimum, proficiency in one programming language. Something like C++ Primer is 1000 pages alone, and while all of it is important, it is just "tools" just like a year-long econometrics sequence is just tools. Learning how to use all of that in real projects will require yet more reading and countless hours of trial and error. You also need to become familiar with frameworks/libraries for your target language/system. This may be something like Qt for GUI development, or a video game engine, or some JS Web framework...
c++ is not that useful for jobs though, it has a niche in embedded or HFT but that is it. not many jobs in it.