How does one move on after breaking up from long, deep relationship? 36M 36F

Me and my girlfriend recently broke up. We have been friends for 12+ years before dating and we believe we have spent more time with each other than anyone else (I know I have with her, but I'm not sure if she has with me, as she has been married and has kids), having spent many nights hanging as friends and later together as lovers.

We had tons of sex (unprotected, she is the only one I've had unprotected sex with or given oral to, and the only woman I've fallen in love with), went out to eat a lot, went to events, I slept with her in her new house when she got it, I interacted with her children each individually, etc. We talked all the time but that was more of her talking and me listening; she talked way more than me. But she did show repeated disinterest in hearing about my day, I noticed, as I hardly fully explained my day to her.

We got into another argument a few weeks ago and she seemed to change. Usually during arguments I take all of the negativity and blame, get yelled at, and over talked to the point I began to speak very little, which and times would not help because then she'd say I'm clamming up or shutting down. This time, we argued because I was furious that she gave another man her number. She gave a client her number who told her he doesn't want to date women atm, just have sex and sexual experiences.

She gave THIS CLIENT her number. Men ask for her number all the time, and recently a different client asked, whom she rejected, but she gave THIS GUY WHO CLEARLY HAD SEXUAL INTENT her number.

One day we were waking from sleep and things had been feeling good between us, so I laid my head on her to cuddle, which usually the opposite happens. She checked her phone and exclaimed "WHY THIS GUY TEXTING ME SO EARLY?!" and I begin to inquire who, assuming it was her x husband, who had been complaining to her the prior day. Then she tells me about the client she gave her number to and my heart sank, right there in bed with her. I literally felt ALL of the blood leave my morning boner (which was particularly strong this day) and began staring out the window, thinking. She caught on.and said don't get all quiet and talk about it, so I began to tell her that this guy is thinking of her sexually, which is why he texted her at 7:00 in the morning. I told her that it was a turn off and explained that a man texting someone that early who he's obviously attracted to and spoke sexually with indicates that that is what is on his mind.

She took the focus away from that and said that I was not angry. I was not yelling or angry, rather annoyed and heartbroken. I felt unheard and I felt that she wasn't trying to hear my point of view, even though she asked me to see it from her point of view. She said she was with the client and her husband was texting her bothering her when the man asked her for her number and she just gave it to him to be done with it real quick.

We went out that night to the harbor and you're not going to believe this.. she saw the man out at the harbor. He kind of just stared at her as he was passing. I stared back at him to get a good glimpse of him.

The next day we ended up going to a spa and taking showers in separate men and women's area. I'm still extremely pissed off about this occurrence but I'm trying to calm down and give her a nice day. As I'm coming out the shower to go to the main area she texts me saying that he was there.

I automatically begin fuming in absolute anger because she should never have given this person her number. So I text her immediately and say you need to stop talking to him, which is something I assume anyone in the relationship should not have to do. She says okay. Ask her where she is and then go to her. At this point. I'm so angry. I'm just ready to fight the guy even though it's not really his fault.

So we're at the top of the spa and I'm expressing all my feelings that she wouldn't listen to before. How she shouldn't give a man who's talking sexually to her her number. How dead obvious it is that the man was trying to establish rapport for potential sexual action.

Much like the first time but worse, she tells me that I'm making a scene and I need to stop "gesturing". At that point I told her I don't care and that I don't care about these people. I felt devastated, annoyed, and unheard. Then she told me to go away.

At this point I realized that perhaps maybe I am doing too much and calm down. I apologize and tried to ask what can we do here? But she said to just go away. If a woman asks me to leave I must leave. So I left her.

I was considering what had happened and decided since we're here. I may as well enjoy it so I want to enjoy the rest of the spa without her. I kept thinking about it. I didn't know what to say and I felt like I actually didn't want to be around her after a while. She texted me to come to some event during that day but I missed the text because I was in the sauna and my phone kept overheating.

We ended up meeting each other at the top again and we sat beside each other and talked for a while, then I went into the hot water. At this point it was extremely awkward for me to attempt to make any type of conversation. I have never felt this with her before. I usually am the first one to apologize and try to fix the issues but I just couldn't do it even though I tried.

Later I went to get some food and after eating I felt like I was warmed up enough to be near her and speak. Just at this moment she comes up to me and says well. We've been here all day separately and we may as well have come separately. Then she goes absolutely nuclear as we leave and drive home. She says the nastiest stuff she's ever said we break up, she keeps saying horrible horrible things intentionally trying to offend me (she's done this before but this time was way worse), and now has me blocked and won't respond.

I've been feeling devastated for the past couple of weeks but I'm beginning to think perhaps this is a good thing. I do love her and she was the first one I've loved, and she loves me (at least she said she did) to the point that we had even talked about and considered marrying each other.

At times I feel grief as though it should not end this way. We've been in each other's lives for so long. We've shared so many moments together and have been the firsts for each other in various occasions.

How does breaking up work? I may be older but this is my first relationship. I am anticipating waves of grief, but after seeing that she's unwilling to even talk, I'm beginning to look at the bright side.

I'm open to any advice or warnings as to how I may feel or what I can do to make this situation better or to just brace myself for the impending pain.

Thanks for your patience and reading.

TLDR: Long-term friend turned girlfriend blocked me after spending nearly every day together. What do you recommend?