An ex I walked out on last Christmas reappeared via email asking if I’d be in town so that he can give me a gift he’d previously bought me. I was pleasant, said I wasn’t coming to town but my stomach immediately knotted up. He’s bad for me. How do we move on from ex-loves who still have power to hurt us?
One thing that makes break-ups so difficult is that we have a tendency to encode (aka save and store) the more pleasant memories and repress the unhappy ones. When we're feeling vulnerable like, oh say, at a major holiday during a pandemic we recall positive memories of feeling loved and supported to get us through.
It doesn't at all surprise me that this man decided to wait until Christmas to give you a gift he had 364 other days to give you. Understand that this choice was likely intentional. Manipulative, even. Is there no postal service where he lives? UPS? Fedex? He chose this time of year for a reason and a selfish one at that. Would a good person, one looking out for your well-being and care, take advantage of you like that?
He's not thinking you. He's thinking only of himself and what will help him achieve whatever goal he has set. That knot in your stomach was your brain sending a distress signal of impending and threat to the rest of your body. That's not how one should feel when they hear from an old flame.
Since you mentioned this guy was bad for you, I'm going to assume that means your relationship was toxic. It's very likely that what has a hold on you and what keeps you under this guy's spell, so to speak, is what's called trauma bonding.
Toxic relationships tend to be cyclical in that there are constant highs and lows. Things are great until the aren't. The abuser (or abusers, as sometimes two people can just be very toxic for each other) acts out, the partner feels afraid, the abuser apologizes, things go back to normal for awhile until the abuser acts out again. Every time the abuser returns to being affectionate and loving, their partner produces dopamine. Since dopamine plays a role in addiction, it's common for people to seek out the approval of the abusive partner just to feel another surge of dopamine. Throw in some oxytocin, cortisol and adrenaline and your brain struggles to think reasonably, which is why so many people stay in abusive relationships.
All that said, the first thing you want to do to break free of this guy is something you've already done. You left! That's probably the most difficult part of the process.
Now you have to keep him away from you. No contact. No dropping by with gifts. The minute you see him, you're going to start producing those chemicals and your judgement will be affected.
Your next goal is to see this man for who he is, not for who you remember him to be. That means going through your mental Rolodex and recalling the bad times. You need to look at your relationship objectively and not through a dopamine haze. Conjuring up those memories will help you change the anchors from positive to negative. When you remember him as someone who caused you great turmoil and hurt your emotions will follow.
As cliche as this might sound, journaling is excellent for performing a brain-dump and sorting through the emotional garbage that comes tumbling out. In fact, writing out just how poorly this person treated you could assist in gaining a new perspective on him, you and your relationship.