What's wrong with my sunflowers? (growing, backyard, leaves, bloom)

[orangecapo]

Hellooo.

I've been having some troubles with my sunflowers and I was hoping someone could help out.
I have 6 sunflowers growing outside in my backyard, and the tallest one has a pretty thin stalk and I've had to keep it supported for most of its life.
I'm not totally sure if this may be how sunflowers are supposed to look once the seeds are starting to form, but if you could take a look:


And let me know what you think?
I have another one, that's already bloomed and is starting to have seeds, but this one is growing multiple heads (?) Another one of my sunflowers has also shown a bud near one of the leaves like this:

Here's a side view. And, there's more of them that the picture shows.


Also, my sister advised me to check on a forum to see if anyone knows if the way some of the leaves are could indicate a deficiency in something?




What's going on with my sunflowers??