On the other hand, you are not hopeless! I've heard people just write without respecting dissonance at all, like they had never heard music before. What you've made is approaching drone - the lower whole notes made me think that was where you were going, which I love. You just need a little bit more rhythmic variation, some frills away from the center line (ostinato) change up the velocity/volume of each note, and push around the stereo placement/panning. It'll sound a lot happier, and it'll give you more ideas to play around with it like that.
Above all listen to what
you think is wrong with it, because criticism from others ignores what you're hearing and what you enjoy - your ears are not lying to you on the latter, but thinking objectively about the former is much harder. Basically there's composition, and then there's translating that into music and hearing your composition. The tug of war between the two is where you improve both.
Also, it's worth mentioning that midi is generically hit or miss because what other people are hearing is not at all consistent with what you may be working with - if you want to share it, it's going to be difficult to give a good impression if the volume of the samples inside the Soundfont are completely wack compared to yours. LMMS, or the free version of FL Studio is great for this, you can import midi and assign each track to a separate instrument, even split it up across new tracks into fast/slow violin notes for a less mechanical feel, while still working with the tools your course is using for actual composition.
More than just volume, you also really have to listen to the vibrato and characteristics of the instruments you're using to get it to sound reasonable. It'll sound especially good if you can manage to grasp the tempo of the vibrato, in the violin and whatever else you choose to use, and match it to the tempo of the song in a way that makes sense with the timing. Takes a little practice to hear.
Some better soundfonts might help, if your course allows for that! I use Squidfont Orchestral for everything but violin:
http://soundfonts.darkesword.com/ and otherwise I use All Around Violin:
https://dl.dropboxusercontent.com/u/46645289/aaviolin.sf2 (not sure where this originated from, the only site I found it on is a shady-looking soundfont aggregator) Both are really well-balanced recordings to begin with, IMO - while they aren't even close to a professional sample library, they can be beautiful with some effects layered over-top to mask their repetitions. If you're interested in hunting for more, this is the thread I got them from to begin with
http://www.newgrounds.com/bbs/topic/1200140