Dear Cecilia:
Maybe he contacted you to.. make nice, to soften the breakup by being nice and polite, and when you responded with a bit more than nice and polite, he withdrew. It is a possibility. Because of you feel addicted to him (“I was falling back into something addictive”), giving you nice-and-polite is like giving a drug addict just a little bit of a drug.
“I have now convinced myself not to recontact, and if he does, I will ask him not to do it anymore”- good idea, and I would tell him not to contact me anymore, if I was you (instead of asking him). Back to the drug imagery- total abstinence is a must when it comes to overcoming a drug addiction.
Him seeing someone new- that triggered your deeply rooted feelings of being inferior to others. I know how that feels.. I felt it most of my life. But not anymore, so deeply felt beliefs can change if you work on it continuously for as long as it takes.
Thank you for posting an update, good to read from you anytime!
anita