I admire you for wanting to make changes within yourself and break your pattern of behavior, as you said. I admire that you recognize how this old behavioral pattern is not actually helpful to your life and. your emotional equilibrium. The only way I know to change ourselves is to do the hard work of actively changing ourselves. I personally have found several books helpful to me in learning of my own dysfunctional ways of thinking and ways of behavior. You’ve started new patterns already by not drinking and practicing mindfulness, which shows a lot of inner wisdom and reaching for self love. Sometimes when we cling to other people, it is our own emotional need or pattern of thinking,  that makes us do this. I often recommend reading a book on codependence or going to CODA meetings (some are online) or any other codependency support group. I have liked The Happiness Trap, and The Road Less Traveled, too. Which are not about codependence but about healing ourselves and finding our paths in life.

What I would also suggest is you start to journal each evening about the things you wonder about and maybe start with the clingyness. Does it feel like the guy is abandoning you and this triggers some kind of panic or anxiety so you long to get him back? Does it feel like you are not important or valuable if you don’t have a man in your life? Do you need approval from others to feel okay about yourself and when the man starts to disengage from you, do you think this means you aren’t okay? What drives this within you is your “homework” to start with. Take your time, just write it pen to paper and don’t censor yourself, let it flow no matter if short or long. If it feels like you can’t do this on your own, a good therapist can really help in many situations.