I did a course over coursera "Computational Investing" and tried building my own trading model, but it's hard . you win some and loose some. Needs 100% of effor

I did a course over coursera "Computational Investing" and tried building my own trading model, but it's hard . you win some and loose some. Needs 100% of effort as it can't be done in parallel with regular job . I need some motivation here .