Just found out I'm paying over £200 more rent than my housemates, am I being unreasonable being annoyed at this?

Just moved into a flat and everything has been going well, I was subletting for a month here but the contract & references have all been sorted so there wasn't any issues.

That is until I saw the rent split that was agreed by the tenants (housing agency don't care as long as full amount for flat gets paid) and I'm gobsmacked. I've included a picture at the bottom so you can get an idea of the room sizes, shapes, and rent. If you need actual dimensions let me know, the picture is a bit blurry.

I understand my room is larger than the others but I'm worried I'm getting completely ripped off here. I've only just stated renting so I'm not sure if I should just accept it.

https://imgur.com/a/465SKGJ

(Mines bedroom 2)