Messed up my Releationship and feel full of regret

I messed up my first relationship, my first love and the only person I ever really loved and ever really wanted. I basically had to convert for us to be able to marry but we didn't stop the relationship and waited for me to convert which probably would have been the smartest way but we were young in love and Already together for 3-4 months when we found out that I had to convert. Since that day our relationship was different because both of us were never sure of how long this relationship would be able to last. Both of us sort of tried to keep the topic as unmentioned as possible. We both didnt talk about it alot which was a big mistake. So for me the male part there was always this wall which stopped me from loving her fully and from comitting 100% because i didn't ever really like the concept of religion, which i told her but we still wanted to try. I just didnt try hard enough, i was often really scared of bringing up topics that i thought about regarding the religion. Because I was scared it would lead to a discussion and in the worst case to us having to break up. Or when she did things that she wasn't supposed to do or i thought like yeah isnt that supposed to be done differently. I mostly kept my mouth shut. I somewhat tried to find my way into religion but just wasn't able to (i couldv'e tried a lot harder looking back) but i also did it the wrong way which i know now. long story short, I always tried to keep her as far away as possible while still loving eachother, so less gifts, less flowers, less dates, less meeting, my family, not nothing just a lot less than we both would have liked. Which is something i never really openly comunicated about, I just thougt i would keep it up this way and if I am able to convert I will give it, 200% and give it my best when I can really start loving her like I always wanted to. This was also a way of safety because if I wasn't able to convert I wouldn't have given it too much and the Pain wouldn't be so bad, (at least thats what i thought) and she would be able to move on, instead of grieving about our relationship and thinking that she won't be able to find a guy like me again, or being depressed for an amount of time. Yeah long story short, she Broke up with me, (we were really distant at that time I worked alot and we didn't do a lot of things together either). But the reason she mentioned was religion i mean although it was a rough time for both of us we still loved eachother, and besides me not really expecting the breakup. I then started really taking shit serious and just filling my head with so much damn information, and started praying, because i thought ok i messed up so bad now or never, i don't want to convert in a few years and regret it for the rest of my life. (it was not like i didn't know anything about the religion or didn't like it I just never had a feeling for God that was mainly why i was so against converting in the first place because i first wanted to find a real connection between me and god and really start believing first.) After praying and really overstimulating myself with information things really started to make sense, and i also began to somehow have a connection to God and shifting my World views in some parts. Yeah there are some more things to the story but I think that would be too much to go into detail. I basically had a lot of hope ending the Relationship. Our last conversation was sort of like Yeah i don't feel good i cant concentrate on anything etc. etc. and I thougt ok I don't want her to feel this way espacially since she had to study for her entrance exam for university. And from my point of view it was sort of a kind of Break from the relationship to find ourselves, I didn't communicate that to her either, which was a big mistake, i could've said something along the lines of okay i want you to get better would it be okay if we take a break (no contact for a month or maybe more) and if i am able to convert, good and if not then we both part ways. But I didn't, I thought it would be more manly or mature that way because if we wait for eachother for a month she would maybe keep on feeling the same and wouldn't start feeling any better. And i didn't want that. oh and also the Last message from her was ''Fi amanillah'' which means something along the lines of I will leave you in God's Hands, or may God Protect you. Which as may be understandable left me in hope. Espacially since I knew how close I felt to converting.

Eventually I was able to convert. And then waited to long to tell her, I sort of waited for a sign from God if we are right for eachother and if its supposed to happen, he will give me a sign, yeah that was probably the most stupid thing i have ever done. Because God doesn't sent you a fucking voicemail or an invitation, I have met her again two times after breaking up I think about a month later and I had the Chance to tell her, I was just way to scared that she maybe wouldn't want me back and interpreted things wrong that were said those two days so wrong, I thought yeah I will probably see her again I will just wait for the next time and then tell her (i wasn't completelly sure if i wanted to convert at that time but I was so close and looking back I could have at least told her how far I was or that I learned how to pray on my own,)

Yeah so when i eventually got to tell her which also didnt happen in the way I intendet to, (I wanted to go and visit her at work with flowers and say sorry and that I am ready now) I called her on accident and she called me back and i told her that i miss her, thats when she told me yeah sorry i have to tell you something I met someone. That was roughly 3 months after the Break up I thought she would sort of feel the same way I did and wont go into anything new for a while. Which she also said herself when we broke up but you never now how things go, and i mean I knew that I left expectations low.

We were together for more than 2 Years and i found out she met this guy, 3 Weeks after we broke up. maybe even earlier but 3 Weeks was the first time she thougt about him in a Relationship type of way.

I feel full of regret for being to scared, and not telling her earlier there were also different things that went wrong in earlier parts but those are things that are normal and that just happened, and that we were to young and naiv to do right the first time. But these last few months just make me feel horrible, because i know i had it in my hands to at least some degree. I messed it up and she was the love of my life and i am just so scared that I will never be able to recover from it espacially since its my own fault.

I don't want to feel Regret till i am an old grandpa. So my question is if someone has had a similiar experience will the feeling of regret and self hatred ever get less? And have you found love afterwards, and I mean real love someone that made you feel in a way that you didnt need to griev about that 1 Person anymore. Thank you