H -
You know that I am a nomad. I have - over and over - left stability for exploration. It is how I grow, and when I am trapped in a daily normal, I am less myself. I'm a rapid changer. This has cost many things - most specifically, I attribute my lack of partner relationship on my nomadism. It has also impacted my relationships with friends. We live in an internationally connected world, so I am doing a better job of building a community without borders. Nonetheless, as I hit my third year of living in a place or doing a certain job, everything gets easier and starts to make more sense. Most people would relax into certainty, but it makes me uncomfortable, and I start questioning my life direction and make sweeping changes (like moving to another continent, or quitting my job to start a brand-new career). I've been very hard on myself about this tendency, but am coming to accept that it is just the story of me.
So, all that being said, when I read your post my immediate reaction is "GO!" There was no hesitation. You are brilliant and dedicated; you will either re-develop your career from that place or in a different place. Taking a break and gaining a new perspective is never time wasted, nor is spending special time with someone you love very much who might not be around for much longer.
You were very happy the last time you visited your father; the only thing that appeared to challenge that happiness was feeling somewhat torn between your experience of being "home" (and moving at a different pace) and your work obligations and identity.
You are like me in that your "small business" is yourself; your brain and capacity are the product you sell. You can do that from anywhere. While there might be a moment in which you wake up two years from now and realize that taking a break cost you minimal income or made re-entry into your profession just a tad challenging, it is more likely that if you do not go, you might wake up two years from now feeling like you missed (forever) a distinct opportunity to really settle into a meaningful shared experience with one of the great loves of your life - your father.
Additionally, we never know where destiny is pulling us, or why. There could be impacts on your professional life that take you further than you expected. You really just never know what is going to happen next...