She said she had no time for our relationship, but made time for everything else. Struggling with self-blame. How to move on?

I broke up with my girlfriend (25) 1 month ago (I am 32) and I really can't seem to move on. I feel completely lost; I can't work and just stare blankly ahead at my desk in the office. Today I even had to step out to cry, despite being a grown man working as an IT manager.

In short, my girlfriend never had time for me; we met only once a week throughout our 1-year relationship. When we broke up, she told me that she couldn't change this no matter how much she wanted to, and that despite loving me, we had to end it. After the breakup, she reached out to me once to reconcile, but during our meet, she only repeated that she didn't have time for me. She said that it was painful for her to see how unhappy I was about spending so little time together, and that she was also unhappy because she was constantly anxious about when we would be able to meet next.

Since we broke up, within just one week she arranged a 4-day trip abroad to the city where her ex lives. When she left for this 4-day trip to her ex's city, I asked her about it. She told me she wasn't meeting him, that she had blocked him, and that she was going with a female friend. However, a few days later, after we met up, she unblocked him and followed him back. Since our break up she goes out partying and constantly has new male followers. Ever since I found this out, I've been blaming myself, wondering why she suddenly has so much time after the breakup when just a few hours together was a gift while we were a couple. I don't understand why, if she loved me, she didn't dedicate more time to me when she could always manage to make time for partying, traveling, friends and movie watching alone. I am completely devastated, thinking she might have broken up with me because I became boring to her, since we only met late at night after her work from 10 PM until morning (I'm working in a 9-5 job). I was usually exhausted and couldn't organize any activities or go anywhere. So, I would have gladly been exciting and adventurous, but I never stood a chance to show it because there was no shared quality time in our relationship.

I also don't know what to make of her ex-boyfriend, who was constantly texting her during our relationship, and whom she originally broke up with because he cheated on her. Even though she blocked him, I don't understand why she unblocked and refollowed him if she no longer feels anything for him. During our relationship, she never told her ex or the men who approached her that she had a boyfriend, despite my asking her to, because I knew they would leave her alone if she did. After the breakup, I blocked her so I wouldn't keep checking her profile, but I can only last a few days before unblocking her. Whenever I do, I always compare myself to the men she follows and to her ex, blaming myself for not being like them.

I also feel huge guilty wondering what if she texted me while she was blocked, didn't get through, and is now angry with me. I try to distract myself with work and working out, but I start and end every day with this self-torment.

I feel that I was a caring boyfriend, I really put in the effort, tried to organize plans whenever there was an opportunity, paid attention to her, regularly checked in on her, and supported her through difficult situations.