Here is some advice that I find very helpful. From Joshua Miller, via LinkedIn:
"15 Things You Should Never Apologize For | Joshua Miller | LinkedIn"
I could quote key items from the list, but I'd just end up quoting the whole list. So read the article. :)
And the summary:
Final thoughts:
When it's all said and done, the best advice is to be true to yourself and don’t worry too much about what other people think. Over apologizing or saying I’m sorry when it’s not warranted can reduce your self-esteem over time and can alter how others perceive your level of confidence. In short, say, “I’m sorry” for when you actually made a mistake.