Your ex will never regret the way they treated you
If you break no contact, if you look for reasons to continue to hold on and if you continue to use the nostalgia and life you shared as a means to keep them in your life.
They can't regret mistreating you and they can't miss you if you're always around, always trying, always trying to fix something that in most cases, is no longer fixable. It's done. Finito. Finished. It happens to the best of us, but you have to move on.
The only way your ex will regret the ways in which they treated you is if you never speak to them again and that you become absolutely ruthless about your goals, your life, and focusing 1000% on you. You cannot perform your way into this, you either have the discipline to do this or you don't. If you don't have the discipline and still want a shot with them, then you can keep orbiting around them but as long as you're available to them after they've left you and mistreated you, you will always be replaceable. You will always be easy to leave. You will always be easy to mistreat. And your ex will never learn anything about the breakup.
In essence, this post is not about engineering revenge or doing a tit-for-tat. There's no such thing as revenge when you're working on yourself and removing your focus off of them and putting it towards yourself. You can't pretend your way into this, you literally have to just do it.
As for me, I'm committed to never speaking to my ex ever again. Not as an act of cruelty or revenge but because that is how I'm choosing to move forward with my life; I have no desire to revisit what we had, nor do I have any desire to create a space for her in my life. I don't want to be friends with her. I don't want to be cruel or unusual towards her, there's just no necessity for her to be in my life. She is not an asset towards my own development, she's not someone that I want to continue contributing to my life in any capacity.
Our relationship was fantastic and really great too, however, that was then and this is now.
She broke up with me and I opened the door for her to walk right out of it. When I closed the door, I processed the breakup, I learned a lot about how I spent the last 5 years and now I'm focused on moving forward.
I will never speak to her again. I'm not punishing her nor am I being petty. I'm choosing myself. I chose her for 5 years and I'm glad that I did. Now I'm going to spend time choosing myself and prioritizing myself. Prioritizing myself means focusing on my healing, surrounding myself with people who show up for me in the same ways that I show up for them, hobbies, my career, finances, building myself to the person I want to be proud of 10-20 years from now. That entails never speaking to her again and never looking back.
I think it's perfectly okay if some of you want to get your ex back, I don't think there's any right or wrong way to approach this. If the relationship was healthy and your ex is receptive and you guys are actively working towards a better communication (and have a plan of action on how you will move forward together), I don't think there's anything wrong with that. My hope is that you still prioritize yourself until they demonstrate that THEY are actively creating a place for you in their life.
My relationship ran its course and I got exactly what I needed out of it. I'm not cutting her off for the rest of my life to engineer regret in her; I recognize that it will be an inevitable side effect after enough time has passed but overall, that's not my goal.
On the other hand, I also know if we don't give our exes time to process and make ourselves completely absent from their lives, they can't recognize the good we brought into their lives and the lessons they learned with us.
Our exes at this moment are mostly focus on self-discovery and finding dopamine hits wherever they can find it, they're not wrong for that but as long as we're available to them, they will continue to overlook us and they'll see us as a depreciating asset: something that is too old and reliable, something that is unremarkable and maybe even annoying.
If you don't want to be annoying and you want to make impact in someone's life, they have to miss you, they have to see you as someone who is working on themselves and is so involved in their own self-interests and goals that anything else has to come second. Fixating on your ex needs to be your very, very, very last priority if you want a chance at them coming back into your life.
If you're trying to move on, they shouldn't even be on any kind of priority of yours, you should be working hard to eliminate them from your psyche. Time alone doesn't do that, intentionality, getting rid of old things that remind you of them and anything that prolongs your attachment should be in the garbage, donated or sent back to them.
It's taken me a long time to even get to this place of acknowledging that I don't want her in my life in any capacity. I no longer feel guilty about it nor do I feel a twinge of sadness. I just know that if I'm not ruthless about me, nobody else ever will and if I don't love myself, I will always be reliant on the whims of someone else's intentions or inactions and I deserve so much more.
And so do you.
tl;dr YMMV but if you want your ex back, remain scarce. Let them put some effort into communication and develop a game plan on how you both will get back together and create a brand new relationship to enter. That can't happen if you're constantly around, not developing yourself and growing and just being lackluster about your own life. Don't treat your life as lackluster just because they're not in it. Depression is not easy to navigate but you have to literally fight for your own sanity.
If you're committed to moving on, never look back. Never speaking again is a choice I'm making for myself but I recommend you do what works best for you; not out of malice but because you deserve to focus on you and to pour into yourself.
Again, nothing wrong if being friends later on is your aim but again, YMMV and only you know what works for you. For me, closing this door, never looking back or revisiting the memories is how I choose myself. Ruthlessly, relentlessly and without compromise.
The greatest love of all is the love you give to yourself.