A software license which prohibits people from forking and monetizing your project would not be an open source license according to the open source initiative. Also, unpublishing an open source project does not revoke the license to those people who already have a copy of it. So you could close future versions of the software (assuming you didn't incorporate any user contributions without securing the copyright to them), but that doesn't prevent people from still redistributing and building upon the last version you released as open source (if someone made a backup).
What you actually seem to want to do is not open source, it's source available. This is a model where your sourcecode is public for people to view, but your retain all rights to it, so others can not (legally) fork or redistribute it. Keep in mind that you can't technically prevent people from doing that, only legally by sending your lawyer after them when they violate your terms.
If you decide to go for a source-available model, then Github might not be the right platform for you. While you don't have to add an open source license to a Github project (even though they encourage it), many people will (falsely) assume that when it's on Github, it got to be open source and they can do whatever they want with it. Also, the whole Github platform is designed around bazaar-style open source collaboration. This includes the ability to fork your project with one click, which you can not switch off or prohibit (Section D5 of the terms of service). It might be better to host the sourcecode on your own website where you retain control over how it's presented.