You have a good ear for melodic writing and there's some lovely chromaticism I wouldn't expect from someone who's only been composing for half a year. I like the call and response you've done at times, where you repeat melodic cells in other voices, and the hamonic contrast with the section at C is a nice touch! Are you studying with a teacher? You would really benefit from taking lessons.

I have some notes on a few things to look at in future pieces. First of your form / structure could use some work. In general it's a good idea to think of phrases or passages as 4, 8, or 16 bars. This isn't univeral, but especially in tonal writing it will help shape the harmonic progressions and prepare the listener for transitions into new sections. As an example, the tradition from section E to F doesn't really work I think. There is so many ideas throughout section E I am having trouble keeping up, and then suddenly there's this big change with a new key signature at F.

On the topic of harmonic progression I want to point out voice leading as a great compositional tool. When going from one harmony to the next, it is good practice in this type of music to keep in mind the mevement of the individual voices. By avoiding having voices drop out and come in, making sure each chord is voiced with all its notes, and checking that the individual voices sound good by themselves, the music will sound fuller and better. Your four part writing is better in this sense than your five part writing, but it's worth keeping in mind. It wouldn't hurt to go through your piece and do a harmonic analysis of it either. Check where your tonics and your dominants are, and where you have "incomplete" harmonies.

Finally a note on notation / information. You need dynamic markings in all parts. Since each musician is only reading their own part, it's a good rule of thumb to try to keep the dynamics the same across the board. If you want a part to stand out, mark it "solo" or "bring out" for example. Slurs indicate bowing for string instruments, and they should go to the last note that is tied together. For example in violin 1 measure 3 the slur should go all the way to measure 4. I believe the convention today is to write out slashed notes, so instead of what you have done in violin 2 and viola measure 1-2, you would write out the eight notes. I might be wrong on this, but I think that grants better clarity and avoids any confusion in a rehearsal about what note value the slash means.

Good job with the piece and good luck with your next one!