I fall back and regroup and figure out exactly what it was about the activity I enjoyed and try to find another way to "get" that enjoyment. We are changing constantly so no, if you no longer enjoy an activity for whatever reason, by no means do you have to continue! But don't give up on a "larger" activity like "art" or "writing," just re-invent it so you do hands-on collages instead of painting or reading/writing poetry or personal essays instead of working in your journal.

When I was in college back in 1970 I was a history major but the required thesis course came up and I was terrified (had to "discuss with a group of peers") so totally changed my major in my senior year and "moved on." I got to thinking about my life now in my 50s and trying to imagine how I'd feel when I'm 85 or so, looking over my life, and realized I "missed" history and still loved it. Well, I was in a better place and the course was still being offered only in a different way (online and only between you and the professor) so I took it and loved it and got an A and decided to get a second degree in history (I had more credits in history than in my degree subject back when I graduated in 1972) and will get that this coming May.

Let whatever it is "go" for awhile; if it's important to you, it will come back.