Ah, thank you so much! So, I'm also a very visual / audio learner. Sometimes when I see a picture or hear a song, a story comes to my mind. It's not always clear at first - sometimes, it's just a scene or a character or even a circumstance ("what if" scenarios are the best). I've got whole playlists and moodboards of music and pictures that helped inspire me.
You can also gain inspiration from a lot of real world things as well - for example, I personally love Greek, Norse and Native American mythology. They deal a lot with gods, spirits, curses, and on the whole, the theme of man's relationship to the world (and why things are the way they are). So I guess another tip I could give would be find other things you like (art, music, books, video games) and use them to help inspire you!
For the writer's block, I've personally found that there are many ways to combat it. Sometimes it's not sitting down and writing, but it's say: working on a character, fleshing out a world, etc. Working on other elements of RPs/Writing can sometimes unlock my will and further creativity to actually complete something. So if I'm trying to write and my brain is just not producing words, it helps me to turn my energy to something else that's related to what I'm working on. It might not get done quickly, but it does help me get things done smartly.
Hope this helps!