I hastily posted an answer and immediately lost 8 reputation points to down votes. I would delete it but that might be making things worse What should one do other than be more careful next time
Deleting it does, indeed, erase those lost votes and you get your points back.
Deleting answers that are deemed low quality by the community is also desirable in its own right. It helps keep the site clean from clutter. I do encourage you to go ahead and delete it, but if you want help in writing answers more effectively, and that will get up-votes instead of down, I have a few links for you.