Why do I keep thinking about my ex?

[Grandadwasthatyou]

Split from my Dh 4 months ago after 16 years of being together. My decision entirely as I felt we we were 2 different people and he was devastated.
I have not regretted my decision at all but feel very sad especially in the evenings when I am sitting alone. I do not particularly miss him and have plenty of support from good friends and family.
Why then do I find myself thinking about him constantly, where he is, what is he doing, who he is talking to?
And even though it was me who wanted to split I know I will be extremely upset when he finds somebody else.
Why do I feel like this? It is stopping me from moving forward.

It's early days. Give it time. It's going to hurt for a while even if was your idea.

I'm sure you had very good reasons after 16 years, it will take time to heal. Try and not think about what he is doing and think about what you want in life.
If you don't have children, then don't look at his social media, delete him off your contacts list. The less you not see what he's doing, the easier to move forward.

As pp have said, it's still really early days and will take time to heal even though it was your decision. Try and distract yourself when you start thinking about him. I find coming on MN helps me think about something else or getting into a series on the TV / Netflix

Because you are grieving. If you weren't grieving over a 16 year relationship then something would be wrong. You're grieving the loss of what you hoped for, the loss of who you were in the relationship, not the loss of what was.

Take your time and take comfort that this doesn't mean you have made a mistake. Be kind to yourself.

Thank you for your kind replies. I feel so guilty as I know how desperately upset he is but I have had to manage his expectations and tell him there is no going back. I still care very much for him and spend a lot of time worrying about him when I need to be thinking about my own mental health and moving on.

This is my situation too. Separated a month ago. It was my decision to separate and I know my DH is in a decline. He's very depressed and I am worried about him and feel very guilty for causing him such pain. Trying to keep in mind all the many reasons I wanted my life back after almost 20 years. I know my life will be better (eventually) but I don't think his will and that makes me feel bad and I too think about him way too much. I feel a mixture of relief I've finally done it and guilt. No solutions sorry but I'm watching too see if anyone else has wise words.

@takeabrolly I know I made the right decision, I really do but I have lots of support around me and he has none. He is living with a relative who normally he doesn't particularly get on with but he had no other option. He has no siblings, parents deceased and regarding the few friends he does have I really don't think they will be particularly good at emotional support.
He says he has nothing left in his life now to make him happy and I think at the moment that is true.
I feel as if I am the only one giving him support ( over the phone) when I am the one that has caused his unhappiness really.
But I had to think of myself and my own mental health for a change and we wanted completely different things in life.