So after lots of reading and experimenting I personally found that shutting all windows and blinds/curtains during the day and then opening them wide at night when the air cooled really helped.
On top of this I opened the loft latch to give the hot air somewhere higher to escape to. I’m not a fan of sleeping with my bedroom door open but I begrudgingly did this too.
All of these things combined with a fan seemed to make the heat a little more bearable.
I did read somewhere about filling a hot water bottle 3/4 full and freezing it then having it in your bed is really good too as it takes a while to defrost. Haven’t tried it yet though.