No matter what you do, you will always have doubts especially at a time when things are not going according to plan or there is not so much light at the end of the tunnel so to speak, or what you want to achieve seems so far away.

I always try find time for all my interests as well. Granted sometimes it is not possible time money etc, but it's not always about studying the conventional way to learn certain aspects of whatever that interest maybe. And because you are drawn to it anyway it doesn't feel like a chore when learning more or perfecting your skills in it. There is no pressure at that time of making money, meeting deadlines or passing exams etc, but future wise you never know when those skills will come in handy.

Plus if you can make a lil extra change from other interest it's an added bonus. Dip into as many areas as you can is what I say.