I don't really get the 'bad dad' accusations on here. Unless he was extremely abusive or dangerous, then fathers will get contact even if the Op LTB. He will end up with him having sole care of his baby at times.
Just cutting him out over a disagreement over how to sit up a baby isn't an option.
So- what options do you realistically have?
You are both incredibly tired, and it sounds like your argument got out of hand and bad things were said. This is normal, many marriages and relationships struggle, I think the year after first baby is the peak time to split up as it is all so stressful, a huge life change and no one is sleeping well.
It sounds like he is not doing anything too awful- he didn't actually choke the baby, he fed the baby a whole bottle and the OP was worried about choking, but babies do make choking noises and, crucially, didn't choke.
Similarly, I very much doubt he is actually endangering the child by encouraging them to sit up, propping them up with pillows or a bumbo is pretty normal at 5 months.
I think you do have to learn to trust each other. That said, my husband had a higher toleration of risk say when in a playplace, and sometimes I just used to leave him to get on with it on the basis he wasn't actually endangering the children, just being more risk-taking than I would have been.
Keep talking, try not to get too entrenched, there's no right way to bring up a baby and it may be that your ways are different but complementary for the child- it's very good for example to have a quite cautious parent and a more risk-taking one, it evens it all out.