I am making a wood mansion in survival, and I use lots of wood, because I really don't feel like its nice to cut all the trees around your house and make everything look ugly, I have a tree farm. I was using bonemeal to make all the trees grow quickly, I expected that to happen and to continue with my day.
What actually happened startled me. So you see I was using the bone meal, and then this tree grew and I was trapped in a dark room. Then my health decreased, as if I was being hit by a zombie or spider or anything. I died, spawned in my house ran back to the tree farm, searched desperately for my stuff. I found them in the bushes of the tree in which I used

1. Grab your Bonemeal
2. Plant a tree (don't use the bonemeal right away)
3. Get really close to the tree, basically stepping on it.
4. Use the bonemeal
5. You should appear in what I think is the inside of trunk of the tree.
6. You can get away if the bushes don't cover the way, but you can't actually see if there are any bushes, you just have to hope, there aren't any.
The photo is me getting stuck in the tree trunk a second time, luckily the tree was tall, so no bushes stopped me from getting out. The second photo is me out of the tree.