I understand, as do many!
I have had chronic nausea problems for years, so I know that one too. I have found the best thing for that, for me, is using medical cannabis, but it doesn't work for everyone and is not legal where you are....
I love to work outside on my land, but have learned the hard way how to listen to my body and, no matter what, stop when it gives me the slightest cue that it is reaching the point of having had enough. Sometimes that is after 10 minutes! But usually I can go longer.
The really hard thing for me was first, really learning to listen and pay attention to my body because all my life I always just worked through anything. And second, being willing to stop even if I had only just gotten started, when I am just not the kind of person who stops something instead of finishing it.
But when I did learn those things (and it took a while, believe me) it was very beneficial to me. Now, I just go out and start, and all the time I am checking in with my body. I stop the moment there's a twinge. I may still pay for it a bit later, but it isn't ever as bad as it used to be. It's excruciatingly hard to learn to be OK with this, but over time, you do learn, and then it gets easier.
In the meantime, feel free to vent and moan here!