Hi Lottie
In a way pp's are right that if you can accept this is how things are it goes a long way towards making you feel better, but I have to say I am totally with you on co-sleeping, it wasn't for me either. And trust me there are things that can be done if you are willing.
Firstly, can you post your DS's daytime routine i.e. wakeup time, nap times & length & bedtime. 2hrs sleep isn't actually that much for a 9 month old & it may be your DS is overtired & hence the frequent wakings at night. Or it may be he is going to be early to transition to 1 nap & needs a routine change.
Secondly, can I ask what happens when he wakes at night? Is he just a bit restless & shuffling around? Is it immediately full on crying/screaming? And what do you do to deal with this? Do you give him a while to see if he will self settle? Or do you go straight to him? How do you respond? Do you pick him up? Cuddle him? Feed him/rock him back to sleep?
Also does he settle to sleep independently at naptimes and at bedtime or does he need your help i.e. fall asleep on boob/bottle, rocking/cuddling?
Does he have a dummy & is he able to find it in the night & replug?
Is he/could he be teething at the moment or does he have any known medical issues eg reflux as both can upset night sleep.
And finally is he achieving any new developmental milestones atm eg crawling/pulling up to standing? 9 months is quite a typical age for night sleep to go wonky when they are first learning to do these things.
Sorry for all the questions but it will help me/others offer you some more suggestions/advice.
xx