What floor is it on? What kind of sun exposure? Northern, Southern, Eastern or Western?
You may need not only insulated cellular blinds, but also insulated drapes- work well in the winter too.
It is easier and cheaper to cool off a some what cooler room than a hot or very hot room-because every thing- walls, furniture, bedding has to come down or up depending on the season to the desired temperature.
Good Luck.
is it next to a boiler, or airing cupboard if so turn them off \!!!
did you open your windows? do you need a window air conditioner?
Whatever I do my room is always hot about 85 degrees I have two fans and curtains how could I cool my room down