Posting mainly for support, but if anyone has advice, I'd love to hear that as well.

My (37M) girlfriend Natasha (38F) of 8 months broke up with me out of the blue on Monday.

I was so in love with her, I'm absolutely devastated.

When I asked her to help me understand why she'd chosen to end our relationship, she said something to the effect of "I'm not having fun any more. We don't have enough in common. Now that I've gotten to know you more, I don't think we're compatible. I don't like you enough to make me want to continue. It started off about 1.5 months ago that I started wanting to spend less time with you. And now I don't want to spend any time with you at all."

Now, this is the kind of this I would completely understand in the first few weeks of dating someone, even the first 3-4 months. But after 8 months, seriously? The reason you give to break up is "I'm not that into you." That's the kind of thing you learn a lot earlier in the relationship. And if she'd been wanting to spend less time for me for one and a half months, why didn't she talk to me about this at all? I would have been happy to cut down on our time commitment and see her less frequently, and/or to put in more effort to plan fun/new activities. And the part about not having enough in common is plain bullshit - we had shared a lot of common interests and activities.

The other thing that bothers me about this whole situation is that the timeline for when she said she started wanting to spend less time with me coincides exactly what she started a new relationship with Jacob (40M), after which she started dating both him and his NP Amanda (38F). She is precisely 1.5 months into NRE with Jacob, and perhaps a month into NRE with Jacob's NP.

I was happy for her and felt a lot of compersion when she told me about the time she spent together with her new partners. Yet the past 3 weeks, I had felt that something was off. I had this anxiety that she was going to break up with me. But I talked myself down because there was so much objective evidence that everything was perfectly fine. I had asked Natasha, literally a week before she broke up with me, if her needs were being met in the relationship, and she said "yes." She kept telling me how she loved me and how hot I was. We had plans for her to meet my mom, and we had booked a weekend trip and were planning other fun activities coming up.

Every single time a long-term or semi-serious relationship of mine has ended before, there were real reasons in terms of incompatibility that I could understand. But for this one, there was nothing. We were kind and thoughtful to one another. We communicated well to resolve issues (or so I thought). And the sex that we had was amazing. She took numerous steps to escalate our relationship, including telling me that she loved me, introducing me to her friends, initiating a discussion about the girlfriend/boyfriend label.

I can't help but think that the main reason she broke up to me was that she was comparing how she felt with her new partners versus how she felt spending time with me. Natasha and I had a camping trip two weekends ago which was somewhat disappointing for her (rainy weather), but we got along well over the course of the trip, didn't fight. And we had really hot sex. After I went home she texted me about how she loved me. The Monday before she broke up with me, I assume she had spent the weekend with her other new partners. She was supposed to spend the upcoming weekend with me.

I realize that the actual reason doesn't matter and I have to accept that I may never get closure. But when serious relationships ended for me in the past, my awareness of legitimate reasons for incompatibility was a HUGE help to me in processing the emotions to get through it. And this time I don't have that.

How can I ever trust anyone again after this? I did all the right things. I communicated. I expressed my feelings. I was vulnerable. I put so much effort in this relationship to be considerate and thoughtful. I feel like I have learned absolutely nothing from this experience that I can take to future relationships, except perhaps to put in less effort and to keep my heart more guarded. I'm afraid that in the future I will either end up putting up walls, or I will develop a huge insecurity complex.

The worst part is, I'm not even angry at her. I'm just devastated. I still love her. I don't want to love her any more, but I do. All I want is for her to be happy in life. The fact that she's chosen not to have me in her life is heartbreaking--even moreso when she could have chosen to de-escalate our relationship instead.

Has anyone had similar break-ups happen to them? Where you were both deeply in love, had amazing sex, were kind and thoughtful, and you got dumped out of the blue while your partner was in NRE with someone else? How did you deal with it? How did you stop from becoming bitter, jaded, or mistrustful? How did you keep yourself from becoming jealous, suspicious, or insecure when your other partners started new relationships in the future? Were you able to figure out how to screen or to select partners who would be less likely to do this to you in the future?

UPDATE - 28 Aug.

Thank you so much for the advice and the support to everyone who replied. Reading your replies helped me a LOT yesterday. This is such a wonderful community.

Today I'm feeling a lot better. I thought about the books Living Untethered and the Untethered Soul, and I realized that all my pain was coming from inside. I realized that the only thing hurting me was the mismatch between the way I wanted things to work out for this relationship, and what actually happened.

The world/universe doesn't give a fuck about what I wanted. It's completely indifferent. I got dumped, the relationship ended, and that's that. There doesn't have to be an explanation. It doesn't have to make sense. And to be upset because something turned out differently than I would have liked--or because the cause of the outcome wasn't understandable to me--is absurd.

There is a Yiddish expression, "Mann tracht un Gott lacht," "Man plans and god laughs." I'm not religious, but this summarizes precisely how I feel now looking back on this. I feel like I can let this go and move on now.