Stop trying to do so much.
I was on a team that really got good at pushing back on aggressive estimates. You wouldn't believe how much more we got done and the things we worked on were of higher value when we stopped agreeing to add more to our sprints.
It really helped that we got good at doing retros. Where we looked at what we said we'd do vs what got done, and saying, well, next time it looks like we can only agree to X% of what we think we can do.
Like, I know the phrase "slow is smooth, smooth is fast", it'd worked really well for me when doing physical tasks. This was the first time I'd experienced it for mental tasks as well.