They broke up (all those years ago) because my partner wanted to start seeing another woman, a woman he'd had a brief relationship with a few years prior to their relationship. So they broke up, he got with this other woman, seemingly that relationship lasted only a few weeks before she dumped him
^ this makes me think he's a commitment-phobe @DollyDaydream70. he's always looking for the next conquest, while supposedly in a relationship, then when he moves forward to the next person, he starts to reignite the relationship with the person he dumped.
Very dysfunctional.
And the comment about you feeling ill "how's the Coronavirus?" is him minimising and trivialising your needs.
I'm really sorry to say he doesn't have the capacity for the type of loving relationship you need and deserve and I'd sack I'm off just like I did. You'll feel like the weight of the world has been lifted, and your self-worth will come flooding back.
Don't give him the chance to reply, it's cut and run with someone like that, because their ego will force them to try and win you back, they don't enjoy the dumping, they want to dish it out but they can't take it.
Probably some sort of rejection in childhood, but really really not your problem!