Hello IdentityCrisis,
I believe most people exist somewhere along a continuum, with monogamy at one end, and polyamory at the other end. You could be 65% polyamorous, and 35% monogamous. That is to say, polyamory might be a better fit for you in general, but you are also able to adapt to certain monogamous situations. You don't have to be just polyamorous or just monogamous, you can be a little of each.
You have had some difficulties lately, and I feel bad about that. I'm sorry you had that breakup with your fiancée, I don't think you could have been happily monogamous with her because of the disparity in your libidos. As for deleting the social media posts, I would not call that some sinister misdeed, more rather a mistake, or a lapse in judgment. You know now not to do it in the future, and that is good enough. It's not like you can get into a time machine and restore the posts, so cut yourself some slack on that point. If someone questions you about what you posted, you can use your memory of the posts to answer. Otherwise I tend to think you don't need to worry about it.
I hope you'll stay on this forum. Keep reading and posting here.
With sympathy and encouragement,
Kevin T.