If you Google 'the cycle of abuse'. It'll show you that they go from nice to nasty to nice round and round.
If these sort were always nasty, no one would stay would they?
The nice parts are to trick you into thinking they aren't all bad and that maybe you shouldn't leave. And 'there must be something I can do or say, to make them go back to being kind and stay that way'. It's a trap.
They want you stuck looking inwards. Or looking back to who they 'used to' be and trying endlessly to get it back. Thinking 'if only I could find the right words'. There are no right words.
If you ever find yourself trying to explain to someone that obviously hurtful behaviour is hurtful btw - you are in an abusive relationship. (And telling someone that they are a weak link or beneath you is obviously hurtful behaviour).
Anyway, went of tangent xD
Narcissistic abusers hate when you are ill because then your attention is on YOU. Not them. (You are like a TV that is malfunctioning to them. An object. You don't care about your tvs feelings right?). Similarly they hate when your attention is fixed on other things like your family or studying for an exam that matters to you.
You will likely also notice he spoils special occasions like birthdays, holidays and trips that are not about him. Because again, they take attention away from him. And also, doing so, he will hurt and exhaust you. Which is his aim. To break you so you can't leave.
But you are not stuck.
You are married, which means you will get your share of the money in a divorce.
You can claim cms when you are out too.
Speak to womens aid for advice on next steps.
See a solicitor privately.
You've already taken a step many never to and recognised you are in an abusive relationship.
Start taking little steps to get out. You'll get there.