Op are you possibly holding something back? As a pp said the messages v what you’ve said do not tie.
for example.
The ceo states “to make this as easy as possible” which indicates you’ve asked for what you’re entitled to. So he is explaining it simply to you.
he then makes an offer and says this is a “fair compromise”. For that to make sense you must already have asked for something, which he’s rejected, and he’s offering this as a compromise between what you have requested and what you’re entitled to.
he talks about the complaints as “something you mentioned and a separate matter”. And requests it in writing so he can deal with it . So this appears to be news to him and over and above the issue about why you’re leaving.
you also say you “offered to resign.” Which is odd phrasing. And it feels like the stress is rhe stress primarily of losing your job. The way the letter is written shows the stress is not related to the complaints but the fact you’re leaving and losing your job.
Generally folks are often given the opportunity to resign when they face termination, it allows them to get another job more easily. This is backed up by the text messages where you jump to “return to work, you mean you’d have me back?” and they quickly say no. It makes it feel like termination and you’ve been offered to be able to resign to help you.
they are clearly trying to treat you with kindness and be fair. They are allowing you the opportunity to work your notice if you wish, and also during that time to deal with the issues you say you face with legal and compliance officers. Rather obviously they don’t really want you working your notice, but are giving you the opportunity.
however the fact it is their lawyer and compliance officer, indicates again there is a reason these people were involved with you. Were you responsible for something that was non compliant and could have caused a legal issue?
i get why you might not wish to say on here, but if this isn’t quite how you’ve presented it, then I’d maybe thank your lucky stars, bite their hand off and get job searching.