Although the topic is old, but it is extremely interesting and familiar to me. I myself remember how I tried to combine my studies and work during college and had to choose where I wanted to develop, otherwise I would not have survived from fatigue. I can't say that I regretted my choice, because I climbed up the carreer ladder, but I can't say that I would advise anyone. In general, the best solution is to choose one thing and not to distribute themselves on a bunch of different things