I thought i was prepared for the breakup, turned out i wasn't iin?

She(22F) was my(22M) first relationship. We were together for 3 1/2 years. For both of us it was our first kiss and first sexual relations. At about 1 1/2 years into the relationship we started cohabitating sometimes on the weekends and sometimes during the week and at about 2 1/2 years we were basically sleeping in the same bed average 2-4 nights per week.

The relationship was great but we also had many differences. I had basically told myself from the beginning not to expect her to be my wife because of all the reasons that two 19 year-olds don't usually start dating someone that ends up being compatible with for life. That isn't to say that my feelings didn't get very very strong during our relationship though. But after three years our growing differences were beginning to weigh on our compatibility and I felt that the relationship was going to end soon. We even had a talk about six months before our actual break up that was essentially us both sharing our understanding that our relationship was not going to last.

At the time right before our break up I didn't feel like I was really about to lose anything very important to me. I still cared about her so I met with a psychologist to talk about how to break up with her without really hurting her. Not once while I was talking to the psychologist did I think about how broken up I might feel. And in the week prior to us breaking up I was sorta cold to her by telling her I didn't feel like hanging out (something I can't ever remember doing with her before that) because I thought it might make it less of a surprise when we met and had the conversation about breaking up.

So, her and I meet and I bring up the fact our lives are going in different directions and we also have big incompatibilities that seem to mostly only get harder to deal with. She's anticipated that we'd talk about this that night and she agrees that it seems like it's time. I tell her that I don't think we should break up right away but instead take some time to really think and talk. We both start to get emotional, with teary eyes and some crying. We're both still crying a bit and I ask her if she thinks it's better if I leave, she says she doesn't know. I decide it's probably better and head to my car. That's when possibly the most intense feelings of my life hit me.

Once I get in my car I start laughing/bawling like never before. I think I was feeling some relief from the laughter because I hate to hurt anyone's feelings and I was very defensive and caring about her. That being said, the laughter was always accompanied by mourning and tears as well. Somehow it's fittingly pouring rain outside harder than I've ever driven in previously. I'm basically bawling for the next couple hours, but this was only the beginning.

Over the next few weeks we got into a long conversation about whether or not we should really break up. Essentially my feelings completely changed. I wanted to be with her and I felt like she was everything. I had never told her before but I started to say things like: "I want to marry you and have kids" (This was especially unusual because before I felt like I wasn't sure if I ever wanted to get married or have kids, and it was a big deal because that is what she wanted from me) and "I'd rather be with you than be a billionaire" and many more things. I had previously told her all the time that I loved her and that she was the best thing that had ever happened to me. My feelings in the past had been very intense and I one time I had even cried for a moment just thinking about us breaking up but now my feelings had really peaked.

She eventually decided that it was better for both of us to break up, which I had anticipated. I understood, but it hurt so much. I spent the next two days living with her; spending the night, eating, etc. I'd basically start crying a few times every hour and on our last night together it was a flurry of crying and telling her how much I was going to miss her and how much I hated what was about to happen. (She of course too was emotionally in distress and crying but a bit less so but I'm leaving out those details because they're not as relevant to my question for this post). (Also maybe I should note how unusual it was that she was seeing me cry. I can't remember her ever seeing me cry before us talking about breaking up, only get teary eyed. And that's because I don't cry often, it seems like maybe once or twice a year and only for maybe 10 seconds.)

Since the break up about a month ago, like anyone would anticipate, my feelings have gradually changed. Right after the break up I was thinking of all the ways that maybe I could change myself for us to be right for each other, the most extreme of which would be to become a devout christian and a "spiritual leader" (I don't believe in God and see little reason to). But now I'm starting to feel less and less like she is the only route in life I can be happy with. Admittedly though, I still fantasize about all the ways I could be a different person. She has left the door open for us to get back together one day. She said she still loves me, that it would be a miracle to find anyone as good as me, and that she hates the idea of being with anyone else but in the end: "I can't just abandon God's plan for me because I love you." With each day, emotionally I have moved away from loving her and this has helped me to see that rationally speaking it's silly to think it would be a good idea to get back together.

I've left out most of why we were incompatible because my question isn't in regards to whether or not I think we are. I also left out a lot of other details (sorry for this long post despite). Like the title says, I just want to know if it's normal to feel this way after a break up that I didn't think I would react to in this way.

TLDR: When I was about to break up with my gf I didn't think I would be very sad but then when it actually happened I was super upset for six weeks and now at seven weeks I'm still upset but much less so. Is this normal?

Important note: It's common knowledge that breakups are really hard, that's not my question. What I'm asking is: is it normal for someone to anticipate not being super upset over a break up but then find themselves totally messed up? I don't think it will be too common but I want to know how common it is and I would be interested to hear what people have to say about their experiences. Thanks to anyone who has taken the time to read all this or even just the TLDR. Would greatly appreciate some feedback.