Struggling with melodies

[EngineersMate]

I can't listen to your tune but don't be afraid to try different scales, spread out across octaves (open harmony) and maybe try to learn voice leading. I have found that major and minor chords go well together.

[TheTZeds]

The key is to listen and play along so you can work out what the elements of the genre are

So, should I...

To me, your tune sounds like the genre you're going for, completely. Whether or not that's good in my assessment, I'm not working for you.
Specific moves from strangers from the internet like this? The internet is a crapshoot.
Too much information; the person feeding you specific moves may not want what you want.

If there is something you feel you want to sound like, work 'til you can transcribe that; until you know what happened specifically in the tune.
Make your own observations. What are the characteristic intervals? Is there a rhythm using recognizable intervals that recurs often*? What are the *motifs that typify this thing you gravitate toward. If there is chordal content, what in the tune fits the chords absolutely, vs what seems to be other things. Where is there tension and resolving of the tension. This applies to what you did also.

Then if you want advice, form specific questions out of your work. It isn't really a music theory issue, this thread. You have already absorbed certain elements of the style. There isn't a lot of theory to be worried about there. Yeah, you should keep editing if you're not satisfied. If you care deeply maybe in ten or x years you can improvise wholly formed tunes, but we still edit and rework.

I can't truly know why you're not satisfied which I think is going to be true of most of us.

This is such a good response!