Housemate noise

I live with one other housemate and we share the rent 50/50. She’s on the lease (im not) and she was here first so i definitely feel like i have little to no say in whats allowed or not. My housemate says her 17 year old sister is allowed around whenever and for however she likes and so she stays in the spare room directly across from mine 2-3 nights a week then every holidays. The sister uses this place to hangout with her bf.

After midnight they will make noise on and off for hours, exit their room with the sliding door to go and shower at 2 or 3am. They’ll talk full volume at 4:30 and this is when I’ve had to tell them to shut the fuck up cause i hadn’t slept all night and was at my limit.

Now they are staying the entire school holidays and even with rain sounds on as loud as i can stand i can still hear things banging in their room and hear voices and giggling, not to mention the sliding door opening multiple times, waking me up just as im drifting off.

The sisters bf jumped in the shower just before i did just the other morning and used all the hot water after i couldnt sleep all night. I got pissed and said “there’s no hot water left, thanks for that dickhead” and kinda got a reputation for not being welcoming despite me feeling they aren’t being considerate.

My housemate is a very deep sleeper, and at the other side of the house so she isn’t affected by their noise at all.

Obviously i know it boils down to compatibility and so i want to move but im having no luck finding a place since the price for rooms just skyrocketed and are now almost unaffordable. I know im a light sleeper which is brutal, and i grew up a lot differently to their family. I guess i just want to know if i should just be sucking it up? Is what they are doing just normal behaviour and im the housemate from hell? I feel like if i say anything to my housemate im gonna look fussy and controlling so i dont (im too aware im the problem) but all i want is the house quiet from 12:30am-7am.