Hi Fliss,
It sounds like you're starting to take your photographs quite seriously! As you know I'm not a photographer, but I do know of some books that might be a useful as a next step.
For technical support and advice
Freeman, The Photographer's Eye might be useful.
For a start around thinking about the image, then I'd recommend
Berger's Ways of Seeing and for something more image-specific, perhaps
Sontag, On Photography?
You might (or might not) want to get a sense of what contemporary trends are in photography in your area - if you do, your Arts Council funded regional network is a good place to look - I think you're in the Southwest -
a quick filter of 'photography' shares some interesting work.
And I'd recommend
Colossal (Julie often posts links to interesting things from Colossal on here, too) and
It's Nice That to get an idea of wider contemporary trends in the visual arts?
I hope these help,
Sarah-Jane
(Apologies, as these are Amazon links. I'm not keen on Amazon, but you can also buy these second-hand and they're only a few pounds on kindle, if you find e-readers useful)