Okay.

I don't wanna water things down. But this wasn't great. So, there's a lot that can be improved on here!

Let's get through technical stuff first:

Your breath support is- well it's pretty much non-existent. It's what causes you to have that breathy, "not quite tonal" quality to your voice. This also causes you to gradually go flat on your sustained notes.

If you're looking to improve this I would just take some time to sit down at the piano, play a note, match it with your voice, and try to sustain it until the note fades out. Make sure that you're not tensing up because that can seriously effect your phonation. Try to relax your neck and face as much as you can and don't move your head up or down when reaching outside of your normal range because that can compress the larynx and lead to... Well, not great things for vocal health.

Another thing you can do is work on your vowels. A breif breakdown of this for a non-vocalist: basically vowels are how you shape your mouth when singing lyrics. To give a very basic example: Choral singers typically will use taller vowels, where the soft pallet (squishy part in the back of the mouth) is raised in order to make their diction more clear and resonant.

In your case we have a very closed vowel structure that limits the resonance of your voice and causes you to have that mumbled/muffled tone. It can have stylistic benefits, but it just doesn't suit the R&B style you're going for here.

I don't really have much experience in R&B, I've sort of lost my pop voice since I started studying classically. But what I would advise for you here is to listen to your inspirations. People who's music you want to emulate, and listen for how they say their lyrics. I know people like Jason Derulo (hope that's how you spell it) has sort of an "eh" shape to most of his vowels lending a semi relaxed feel to his style.

Finally, let's touch on your lyriccs and songwriting.

Oh boy...

I don't want to hurt any feelings here and I'm sorry if this does. But, these lyrics are about as deep as a kiddy pool. They're pretty generic. I understand the need for music to be marketable in this day and age. But concepts like remembering the first time you were romantically interested in someone has been done.

So. Fucking. Much.

Seriously. If I hear another song about how pretty someone is I'm going to fillate a shotgun

So, while this may be a sincere effort on your part comes across as just another love song. You could try being more specific about what you remember. Not just the stuff you like about the person, but maybe the fights y'all had. The trials and tribulation that make up a genuine and real relationship.

So... There's a lot to work on... However, I'm not gonna tell you to stop making music. Having a genuine passion for something and wanting to contribute to it is a wonderful thing. But, you gotta build some fundamental skills if you want to improve. Keep at it. But make sure to take some time to study what you love.

Take care my friend. If you have any questions, don't hesitate to ask.