The chords are fine. There is some dissonance between them and the melody which gives the composition an uneasy mood, but music is allowed to feel uneasy if that's what you're going for.
My critique would be about the mix - specifically the textural difference between the rhythmic content and the melodic content. The drums sound very dry and clean while the chords and melody sound wet and very lo-fi and they feel too separate from each other. I would either dirty up the drums a bit or bring a little clarity to the chords and melody to make them feel a little more sonically cohesive in the mix. I would also clean up the low-mid frequencies of the chords as well because there's a little wobble in the low end where it gets a little muddy.
I would recommend this book for music theory:
It's beginner friendly, easy to understand, and the information is immediately applicable to any style of music. Music theory is about having a better understanding of the relationships between notes, understanding why some things always sound good and why somethings don't, and how to use those relationships to your advantage on the fly.
Example:
There's a reason the chord C-D-E sounds like shit while C-E-G sounds pleasant: the notes C-D-E are too close together. C-D-E is dissonant (unpleasant) while C-E-G is consonant (pleasant).
That doesn't necessarily mean you never use C-D-E though. Sometimes you want the listener to feel that unpleasantness. Sometimes you'll want the listener to feel happy, so you use C-E-G.
But when you move from chord to chord, sometimes you want a mood that evolves in interesting ways, so maybe you move from C-E-G to C-E-F#. C-E-F# is not exactly unpleasant sounding, but there's a slight tension to it because the distance between E and F# is shorter than the distance between E and G. So moving back and forth from C-E-G to C-E-F#, you will create a feeling of tension and release, tension and release.
Point is, once you understand how the spacing of notes affects mood and feel, you use that knowledge to deliberately create a desired feeling. So, yes, music theory can be helpful.
Watch any videos you can find on youtube - there are many - and play along with them. Get some kind of book you can keep nearby as a quick reference. There are scales and chord charts all over the internet you can just print out and keep on display near your workstation. Whatever you find most helpful.
