It’s hard to know for sure what’s going on. Perhaps your performance and judgment are so dodgy that Manager has to correct you in emails and force compliance with minimal attendance standards.
That’s probably not the case. What’s constructive to focus on is the fact that this relationship has gone asunder. This manager is going to sever you.
There’s a Hail Mary you could try, involving engaging your manager in a serious discussion wherein you explore a path to salvaging the relationship.
But I think he’s a real problem. Start exploring your options.