Baby is a terrible sleeper, nothing has worked

My six month old has always been a terrible sleeper. He’s up every 45 minutes all night long. The longest stretch he’s slept is 3.5 hours. The only way to get him to sleep is to feed him, and our pediatrician shamed us big time recently because he’s supposed to be night weaned at this age and sleeping through the night (lol). We are so far from that, it’s almost comical. I’m exhausted, and so frustrated because we’ve met with several sleep specialists and asked everyone we know for advice, and nothing has ever worked. We even did CIO for a MONTH and it did nothing, except make me miserable. Is this just life until he’s a teenager? I feel totally spent.