So Anita, I took a break and read the thread again to let it sink in. I also went through a few other threads on the site that were on similar lines.
Yesterday when dad called, I spoke to him about what I felt, I hadn’t planned on doing it but it just flowed out of me. I told him that I had felt unsupported by him as a teenager when I needed him to comfort/shield me when mom scolded/criticized me and that while I’ve moved on from all that now, it still disturbs me at a sub-conscious level. Surprisingly, he understood it. He accepted it, understood it and told me how he’s himself felt bad about it for a long while (I was surprised that dad remembered so many incidents and he categorically told me that here and here I should have stood up for you but I didn’t just to keep peace but I know it came at a cost). I don’t know if it was the right thing to do or not but I felt so nice. I didn’t want to live with a knot in my heart against my dad and once I told him all about it and more importantly, as he understood it, it felt nice and sorted.

Now onto my romantic relationship which is my main focus in this thread-

1. You were right, I do obsess about him. But after a lot of introspection (I literally made flowcharts at a point of time yesterday), I realized that all my obsessive thoughts are like streams coming out of this one umbrella thought that I have, and that is at the root of all of it. It goes like this: I loved him a lot- He left me- I was hurt- I wonder if he will ever regret letting me go/ see me as the one that got away. Everything feeds into this major obsession that I have with whether or not he will regret losing me. That is why I keep thinking if I was bad because I question am I worth regretting, and keep thinking if he’ll be better with someone else because that’ll show he doesn’t regret losing me. So that is my major issue. That is the thought that I have to let go. I can’t think of any way to do that besides just telling myself that it doesn’t matter whether he does or doesn’t. The relation is over and that’s that. If there is any other advice that you have in this matter as to how do I end this obsession with constantly wondering if he’ll regret anything, do let me know.

2. Mom had told me this a few years back after one of my breakups with him when I was just waiting for him to be back aka obsessing to a level higher than even today. It had helped me but then I fell back into the relation and back into my previous doubting/obsessive tendencies. She’d told me that God has a plan for you, he does for all of us. He thinks about you. If you keep obsessing over all of this, what should I do, what should I not do, what will he think, will he come back or not, will he miss me/regret or not, you are doing all the thinking and worrying for your life, God will be like okay, she’s worrying/thinking about her life enough for both our parts, so let her do it, I need not worry about her life. Leave some things on God, let him also think for you, let him show you a path, have faith in what the universe has planned for you, if his coming back is what is best for you, that will happen, if his staying away from him is best for you, that will happen. Have faith in the universe’s plan for you and stop overthinking. Have faith that what is best for you will happen.
I just happened to remember this advice and it stuck and made sense. For now at least, it is making me feel very calm. So I think this is what I am going to do, to let it go. Try reducing my obsession with him regretting letting me go and leave few things to the universe and take each day as it comes.
This is what I’ve been able to figure out so far, will reach out as more things clear up.

Love

Jenny