It's definitely good stuff! Worth carrying on with. I think the piano accompaniment is fine on it's own- it doesn't really need an orchestral accompaniment, but that's just my opinion.
The harmonies are nice and the parts go together well, maybe it needs a little more variety of rhythm and texture though? You could add a contrasting section with (for example) a faster tempo, staccato notes and a major key, then come back into the original theme again?
Also, I think it would make a nice introduction to a faster piece (like the fast bit at the end)- You could call it 'Adagio and Allegro for oboe and cello' for example.
It sounds very nice though! I like it lots! Keep going!
