I was with someone like this for years in my 20s and it eventually became unbearable. At some level, "I have anxiety" starts to feel like an excuse, not that the person can control it exactly, but we all have the ability to tell which of the thoughts occur to us are good ones worth listening to and which aren't. I became resentful of how, for example, a nice vacation would be ruined over worrying about a lingering bill for $50 or whatever. It's really hard to be around someone like that long term and still feel like they make you happy and that your life is better with them in it, when it so clearly is materially not better. It's like all the color drains away from life and why bother doing fun stuff since it'll just get ruined anyway?