Oh, bless you. You poor thing.
So we didnt have as long a stay, but my daughter did have multiple admissions (20+) before she was 2, plus a NICU stay to start her off.
Her development was a bit all over the place for a while. Some things were fine, some things were not. I stressed ENDLESSLY. My HV was exceptionally brilliant at doing monthly Ages and Stages reviews, and generally just keeping me calm.
By far and away, her biggest challenges were her emotional regulation. She found it impossible to be separated from me, she could not calm down when she had injured herself, any illnesses sent her into a complete panic.
She is now very nearly 5 and I can honestly say that, except for her neurotic mother, you would never ever know. She still has some areas that she is stronger in than others, but that now looks 'normal' comparison to all those other children in her class who had an easier start, but also have their own strengths and weaknesses.
My biggest recommendation is to connect up closely with your HV. Ask them to support you with regular development reviews. You can also download the Ages and Stages online so you can do these yourself at home too. Any concerns, don't be afraid to ask for referrals to e.g. physio, S&L. Some of these things are available privately and not necessarily hugely expensive so if the NHS is slow and not reassuring you, then you could consider that. And finally - consider some counselling for yourself. I suffered horrendously with health anxiety after things had finally calmed down and needed a lot of support. If you're under a year postpartum then a referral to your local perinatal team might well be helpful for you, even if they just refer you on x