6. Delete your account. Create a new account under a pseudonym. Add a single friend, who can add you to group chats.
At this point, you should have a near-empty news feed; Facebook is only for staying in touch with the group (eg, not missing out on social events) until people have gotten used to texting you to invite you to things.
You won't be able to comment on anything public because if your account gets reported as a fake, you'll be locked out of the account unless you provide ID (which of course you can't do, since it's not your real name).