The Art of Distance

I'm an artist in a long-term relationship, and lately I've been feeling distant from my partner. We both love each other deeply, but we rarely touch or have physical intimacy anymore. It's not that I'm losing interest; it's more like I need art to feel close to him. Drawing his portrait makes me miss him less than usual sex does. Is this normal? Should I be concerned? Any advice for bringing the heat back into our relationship?