I don’t like to say “I’m too busy for that”. If I can’t find the time to do something, I try to say “that’s not a priority at this moment”.
What are you busy WITH if it’s not the highest prioritized items in your life? Isn’t life about finding time for what’s most important anyway?
Having said that, this week has been one of those weeks where finding time on my calendar has been tough. But you find time for things that are most important anyway.
If not, accept it for what it is and free yourself of the guilt of not having got to it. Just admit that it’s just not a priority in your life at the moment. If not, you’d have done it. And the thing is, there is nothing wrong with that as long as you’re happy.