I would be happy to help you "realise" your song with you
My first "feedback" as a co-writer would be that you are trying to cover waaaaaaay too much in your song
You have some fantastic ideas in your back story (sorry by the way!) but there is material there for a number of songs
There are no "rights or wrongs" so I will present how I would tackle brining this song to life with you...
IMHO a good song should focus in on just ONE single emotion/message as you only have around 3/4mins to get your message across and "connect" with your listener
You do seem to have done this by getting to:
in this song I want to say how I'm sorry and If he could find it in his heart to give me another shot at getting it right the second time around
The other thing to bear in mind is that you need to tread a fine line between flattering the listener (ie the "You" lines) and making the singer look good as a song with a sing "whining" is not always the best to listen to
I would therefore use a bit of "poetic license" a make some slight tweaks to the actual situation (but you can still draw on this for inspiration"
We therefore have our perspective
"He" is the boy
"You" is the listener we are telling the story to, trying to get them to "relate"
"I" is the singer - try not to be "whining" or "self absorbed" as this can be difficult for the listener to engage with
I would therefore personally focus on the "regret" theme of the song - ie "I regret I let him go"
This makes the singer look a little more "positive" as you have "let him go" rather than being the one that was "let go" - you can still describe the things you did wrong, your regrets and that it was him that walked away but there is a slightly different spin on it by using this approach as it implies you could have kept him if you wanted to - it is a very subtle difference but should help steer you away from a "whining" song
Adele is a great example of this - even though the majority of her albums are about being "dumped" they still sound "positive" and not too whining and self absorbed
Compare this to Duffy's (who? - exactly!) album "Rockferry" and it was all about being "dumped" but there was a "bitterness" and "victim feeling" that gave the whole album a real "downer" IMHO
The structure could then be...
Verse 1 - introduce the characters and describe the wonderful relationship looking back
Pre-chorus - describe the thing(s) that happened to break up the relationship
Chorus - describe the regret you had because you let him go and you want another chance
Verse 2 - describe life apart - what is he doing now - what are you doing now?
Pre-chorus - describe the thing(s) that happened to break up the relationship (use same lyrics or slightly change them to follow 2nd verse - it doesn't matter if it doesn't make perfect sense, the main purpose of the pre-chorus is to set-up the chorus)
Chorus - describe the regret you had because you let him go and you want another chance (exactly the same lyric as previous chorus)
Bridge - put a different perspective on things - eg describe the things you would do differently if you did get the second chance - try to make this lyric noticeably different to the rest - eg change up the rhythm of the words, if you have previously used a lot of imagery make this section more literal (or vice versa)
Chorus - describe the regret you had because you let him go and you want another chance (exactly the same lyric as previous chorus)
Chorus - describe the regret you had because you let him go and you want another chance (exactly the same lyric as previous chorus)
This gives you a nice "structure" to follow, which will immediately make your lyric more "song like", especially if you are aiming for pop
Verse
Pre-chorus
Chorus
Verse
Pre-chorus
Chorus
Bridge
Chorus
Chorus
I hope this helps set you on the right path to get your lyric finished
The most important thing to decide is how you want to portray the singer and I hope you understand what I am trying to say with regard to not portraying a "victim that is begging for a second chance" but rather "a strong person that made mistakes, has regrets and wants a second chance to make it right"
There is a subtle difference but I think you will end up with a better song if you use the second approach - even if it means twisting the facts to fit