How to stop my friends from seeing my comments/likes on their news feed.?

[NomNomNom]

So, I have a huge habit liking and commenting on pics of sexy women (no they arent completely naked) and ultimately these are showing up in my friends' and families' news feed. You can imagine this is quite embarrassing when mentioned during in-person conversations.

How do you block your likes/comments from others' news feed. They dont show up on my timeline, but do in my activity log and apparently others' news feed so that has me kinda confused. I simply want to be perverted without fear of grandma seeing Im lusting over some big booty ho.
I just changed it to "Only Me" but when I liked some photos and checked my activity log, it says they're public still....