I don't have a problem saying "no" these days. I have learned to set some boundaries in order to protect my peace instead of just going along with what it going on at that time.
No, I don't feel guilty about it. People will use guilt in order to make you change your mind and not say "no" to what they want you to do. The only people that get mad at you for setting boundaries, then they are the reason that you had to set boundaries in the first place.
I don't feel guilty for blocking family members on social media and cutting them out of my life. If you can't respect me, then I don't need to talk to you anymore.
I am sure there is. But as I matured I realized that the guilt was something that should have never been there in the first place, it was just something I thought it was worthy of feeling guilty. Unusual but true.