I find this myself in relation to creative writing. It’s much easier for me to write when I’m going through some sort of intense, emotional experience. So, I’m in the first throws of love. I’ve lost a loved one. I’ve been in a big argument. I think that’s pretty normal and as @DrasticDreamer suggests, it can be cathartic.
What about keeping a feelings journal? That you use to vent your feelings through your writing at these times? It could then act as a tool when you want to draw on those experiences in a creative piece. I don’t just mean when negative things are happening, but when something great occurs. You have a success with your art. Your child does something amazing, cute or just looks at you and your heart melts. Your lover says something that makes you feel tender and/or adored. You go out to the front gate and the birds are singing and you realise how damn lucky you are to be alive. Your child drops around to see you with a bunch of flowers. You talk to some old person at the shops and their reflections on life make you laugh and feel happy. All of these have happened to me in recent times. Perhaps you can keep a notebook in your bag and when similar events occur, jot down how you are feeling.
Another idea is to use writing prompts. Perhaps choose a different positive prompt each morning or at night (whenever you find it easiest to write) and write 200 words (or whatever works for you) on that prompt. Only pick positive topics. I think it’s about developing the habit of looking at things from a positive perspective. And, you could also try to write in third-person. So step outside yourself and look at it from an outsider’s perspective.