Your post reads to me like your trying to convince yourself to quit. I wouldnt want to say either way; except to point out that if your working that hard for a

Your post reads to me like your trying to convince yourself to quit. I wouldnt want to say either way; except to point out that if your working that hard for a company (startup or not) it's got to be one you really connect with. As soon as it starts to become a chore it's pointless. So you screwed up: if the CTO is blowing his top that quickly (assuming it wasn't mission critical updates etc) then to me that smells instantly like he is either stressed (in which case you might like to sit down with him and ask outright if there is issues and whether you can help) or looking for an excuse to fire you.