I have not a very strong mathematical nor statistical background. This fact has not prevented me to work in a data analysis department because of my programming skills. I know the basics of important subjects such as calculus and linear algebra and I have implemented statistical analysis like logistic regression, support vector machines and many others, but always under the supervision of an statistics expert. I would like to learn advanced math and statistics in order to have a better understanding of the mechanics of what I am doing and most important WHY decisions are taken. Since I have time constraints, I have followed some MOOC's in Machine learning and statistics. But after completing the courses I had a bitter taste. I wasn't able to understand scientific papers because most of the authors assume advanced knowledge of real analysis, numerical methods, etc.
Clarification: Since this question has been put on hold I will try to give more details about this specific problem. I work from Monday to Friday. So I can only study on weekends. In the city where I live, there are no universities offering advanced math courses on weekends. So, firstly I bought some e-books on the subject but quickly realized two things: My progress was very slow and it was hard to tie up different subjects in an comprehensive way. I thought I could do better following online courses so I followed some MOOC's whose results I explained before. I'm convinced that the solution implies using Internet resources but by now I've not found a complete and satisfactory solution.