OK. Sick and anxious is your response to your feelings not being heard, but being actively dismissed, and that's why you've felt it during the relationship, and why you're feeling it now (probably even more than before)
The thing you can do, and it is MASSIVELY empowering, is to ensure that none of your feelings ever get dismissed again. Ever ever. Not a single one. Because YOU are going to be the one to listen to them, and validate them, and respond to them. That way, the whole rest of the world can dismiss you as much as they like, but your feelings are still heard, and you still get the feeling you're getting now, the good feeling of being responded to positively, and being reassured.
So, if you feel sick and anxious, don't feel lost about those things. Have a think about things people do when they feel sick. Pick a thing from the list. Do it.
Have a think about things people do when they feel anxious. Pick a thing from the list. Do it.
You might find yourself in a relaxing bath with some candles, sucking a ginger sweet. You might find yourself consuming an alcoholic beverage and then going for a walk in the fresh air. You might find yourself going to bed with a good book for the rest of the day, even though it's only lunchtime. There's lots of options. They might not work. But they will make your emotional self feel that someone is listening. And as we all know, when we have an emotional problem, we don't need someone to fix it; we just need someone to hear us, and make our feelings feel like they are worthy of being noticed. That alone makes a world of difference.