Hi there! I also am a recent art school graduate (let's omit the whole life that went before that) and finding freelance work is not easy for me either, though I have the benefit of a day job to keep me afloat.
So I am not in the position to give any advice, but I will do it nonetheless 
Looking at your portfolio I would struggle to define what type of work you do. Is it editorial? Is it children's? Is it greeting cards? While several pieces in itself are nice, overall they do not present a clear picture of what type of market you want to work in. I believe you should choose a target market and then fill up your portfolio with that type of work. I started this process about 9 months ago, focussing on children's book and slowly cleaning up my portfolio of anything else. Only now I probably have enough pieces to start approaching that market. So far I have illustrated one book (educational) and I am working on my own dummies while waiting for the next one....