I would start to get an account at digital tutors.com or lynda.com to lear things in a proper and orderly fashion. This goes much faster that through Youtube and is in my opinion a very worth it investment.
One approach is to just get started. Make a website. show some fancy graphics/make a showreel (show what you got!) And contact different agencies/bureaus and companies and just bluntly ask if they could use an extra hand for small animation stuff etc. Let the world know you’re doing this and work will come. Get as much people in your network as you can and work will come.
Another thing you can do is create many stock elements/after effects templates. Make them as original and high quality as you can and upload these to stock agencies such as envato,shutterstock and blackbox. Here you can sell your asest. And the good part is since it is digital, if you make something good you may sell it many times. (TIP: VJ elements/loops tend to work well.)
Good luck with both animating/creating and with your PhD!