Definitely a 50s style song. Right from the start I get that. Additionally, the lyrics were a complete story from beginning to the end. The instrumentation was really good too. I'd probably get that cymbal taken down just a tad though.
Vocally/lyrics - it seemed as if you struggled in some spots to fit all the words into the song. A few thoughts on that...
YOUR SONG - But then I stopped... when I heard her on the phone.
When I heard her on the phone CAN fit as written, but it needs to be changed in the way that you sing it. I wish I could sing it for you, but I think you'll figure it out when you listen to it a few times.
YOUR SONG - ...with all you mentioned, not a SINGLE thing do I regret.
You could take out the word single, it would be easier to sing and it wouldn't change what you are trying to say.
Some of the lyrics, the way they are written, are a little "wonky": ex - ...and I'm so happy that into my life he came. Since this is the last line of that phrase, it doesn't need to rhyme and could be sung more like it should be said - and I'm so happy that he came into my life.
Overall, I really do like this song and I think that you have a great start here. The story is a very positive one for a change. Most of the time it would be a story of how he came home to her cheating, but this was not that type of song. I liked that. Thank you for some good, positiveness! (Not sure that's really a word...)