Introducing new kitten to home with resident 3yo cat and no spare bedroom?

[Jillie Bean]

So my parents may be getting me a second cat soon (im 16) and I already have a rescue, who we got a 9 months. He is my baby, and we both have a really strong bond. The thing is, he has never lived with cats properly before...he was given up because resident cats were all attacking the youngster....He sleeps on his bed on a shelf at night, from 11pm all through the night until 7 am when he wants breakfast...he's kind of like a human in that sense haha. He sleeps in my bedroom, and he wont go to bed without me. We have no spare bedroom. Neither my parents or brother would allow a kitten to sleep in their room at night (it'll be my responsibility to look after 99% of the time, but my parents financially). If we do get a kitten, it'll have to spend its time in the bathroom to settle down, as thats the only place we have for it to be away from the current cat. But I couldn't bare to leave a baby all night in the bathroom all by it's self. When we got my older cat, he spent his first night crying until I would cuddle him...and he was almost a year old...a 12 week old kitten would be more needy...Im not sure what I'm going to do...I couldnt have both cats in my room with me right away...in case the older one gets jealous and hurts the baby...obviously when they're used to eachother they'll be in my room. Locking the older cat out is not an option, because I'm pretty sure he gets separation anxiety when he's away from me...he's extremely needy...I may have to spend the first couple of nights back a fourth between kitten and cat..i just dont know what to do...do you have any advice for me? Have you gone through something similar? Thanks very much.