I'm pretty sure someone will accuse me of reading my own trauma into this, but AgentMasterRace mentions also being chronically ill. No mention of timing between Ex significantly imroving and deciding that they had "better options", but the sad reality of life is that many people you love, including friends, will never care for you the way you might care for them, and once they have "better options" will cast you aside, even if you're the reason they have those options in the first place.

Human relationships are brutal sometimes. I still choose to treat others the way I would want to be treated, and some people _actually_ reciprocate, and you eventually learn who is who in your life, but this requires that you be open to the fact the majority won't, and that you will sometimes feel betrayed and used. You just have to accept that it's your decision to make, and decide what kind of person you want to be.

Other commenters are also probably right to one extent or another, the dynamic of the relationship probably changed pretty dramatically and that can create problems regardless.

Anyway, poor old AgentMasterRace probably feels like a depressing episode has turned into something they'd rather it didn't. Sorry for pontificating over your traumatic(?) event with allusions to my own. If I'm reading the meaning of their username correctly though, I feel less bad about it, lol.