Please no judgement or horrible comments.

I Had my little boy in April 6 weeks early. He has never in the 8 months slept through the night. I've tried everything. Then in October he was poorly and admitted to hospital twice which completely ruined his routine that he was in and ever since then he refuses to sleep in his crib just screams for hours (I have left him crying for an hour and a half and not once did he fall asleep) the only time he stops is if I pick him up. Which resulted in putting him in my bed (I know stupid mistake.) he was then admitted to the hospital again at the beginning of December and now he's so restless even in my bed he's awake every hour. I kmow he's teething which doesn't help. But please any advise on how to get him to sleep back in his crib, or how to get him to sleep longer and whether this actually does get any better because I feel like I am failing massively and dying of sleep deprivation.