It's not too short I think, but the current form I think is ABAB, where it could benefit from a third part, a C part, or some kind of an outro. If the B part is the chorus, you can repeat it, maybe building it up a bit to bridge it to the C part, then end with A, or leave it out and use the C as the outro.
I'm not really a musician so take everything I say with a grain of salt. I used to study music theory and singing during my school years but that's long gone now and I can't really remember it all. I doubt I have any voice left either. I did like it though. Singing.
I've been reading some songwriting books which have been useful in terms of analyzing structure,your comments are spot on. Music theory is definitely my weakness. Every time I start to watch /read an explainer I kind of zone out but I know it's something I need to just do, I'm sure it will help my guitar playing, songwriting, lyrical melody etc. I'm shooting myself in the foot by always putting it off 😂