I love to write poetry too!! It just makes me fulfilled, clears my mind.
What I write about? Hmm... It depends on my mood. It can be love, war, happiness and flowers, depression and darkness. Everything has a positive effect on my in the end.
Inspiration. I think about writing ALL THE TIME. There is always a song playing in the back of my mind and I always search new things to write about. While driving, watching TV, walking my dog etc. I think the best inspirations come from the back of your mind, so I read a lot of positive/philosophy books.
I started when I was 12. I was severely depressed and suicidal. I felt like I needed to write down my thoughts, so I did. But after I wrote them down, more and more thoughts just kept appearing. After a week or so, I started rhyming words together. After a few years, I started putting music into them. Now, I'm an amateur songwriter and producer.
Sad story had a happy ending.
It's a great thing you write poetry. Poetry is as big as the universe!
I recommend you to try writing a few songs, it might be your new thing!