The best thing when you're feeling creatively blocked, in my experience, is anything. Leave your immediate surroundings and make yourself act on an idea immediately. Don't hold yourself to a high standard of idea at this point; 'going for a walk' or 'buying a sandwich' count as ideas, but there are two rules:
1) It has to be your idea and
2) you have to impose at least one condition on it.
So 'going for a walk' is OK, but 'going for a walk of exactly 25 minutes' is better, and 'going for a walk of exactly 25 minutes where I see at least three red things and say hello to a stranger' is better still.
The point of this apparently time-wasting exercise is to get your thoughts to switch direction. You've gone from a stew of hopelessness and worry to taking charge of a chunk of your day and setting yourself up to succeed in it. You've also embraced an absurd and pointless activity which should catapult you out of your habitual anxieties. With luck, your brain will flip into a different state: one that's up for a game, and looking around for opportunities to take control.
Taking charge of things can be very motivating, partly because it forces you to adopt a different relationship to your creative work. You also begin to see yourself in a different way. You can be the kind of person who takes charge of their day and their opportunities. All you have to do is decide that's the case. Takes less than a second.
It's not what you know, it's what you are
You may have heard all of this before, but here's why it's important: creativity is not about knowing something, it's about being something. Distinguishing knowledge, skills, feelings etc from one other is arbitrary. It's socially useful, but it's not at all the truth. Any aspect of ourselves loses meaning if it's moved out of configuration with everything else. And the whole collection of knowledge and skills and attitudes in this particular order are you! You are a complete culture of your interests and feelings.
I've wondered why it's very difficult to get into some genres of music without dressing a certain way. I often suspect it's not just about 'embodying a lifestyle', but about the way things simply roll together. Suppose there's a language where they have the same word for the sky that they have for blue. The common thing about sky and blueness might be expressed in one word. That's why people who like line dancing wear cowboy hats. The music and the hat are part of the same feeling. And that's why you talk, dress and move in the way you do: you are not separable. Every bit of you is inside every other bit. You're a poem.
Now that you know you are a poem, you can look for new meanings. You can put yourself in different situations - be a masterful poem, a considerate poem, a sympathetic poem. All the things that you are already can be many more things. Creativity starts with your sense of self. Get yourself out of context. Be surprising. Get out there and grab some new interpretations for yourself, this week.