You guys are easy to please, I was only middle of the pack when it came to drawing skills at University. You should have seen what the painting and drawing majors could do, I was only a photo major but everybody is required to do the foundation program which includes the drawing classes.
And Amelie you shouldn't be so negative, you like to draw and as long as you keep doing it your skills will always improve, drawing is really no different than writing. It is a learned skill, if you can write you can draw, just some people prefer to do it and practice more often and are better at it. If I get a chance and find some of the stuff I did when I was around 16-17 you will see most of it wasn't as good as what you are doing now. It just takes practice like everything else, classes do help, especially when it comes to learning how to see, as well as learning economy of movement so you can draw more efficiently, but you should just remember to have fun. As long as you enjoy it you will keep doing it and improve, and I actually like the style of your drawings you shouldn't be so worried about them. There are a lot of people who can copy a photograph/model, but very few who can do it in an interesting and unique enough manner to get noticed by the artistic communities, although the rest can do very well as commercially.
Here are two homework assignments from my last drawing class back in 2003, the lighting isn't perfect because I don't own a strobe kit to set up the proper lighting so just used daylight and a friends digital camera, and it had terrible white point settings. The first, a study in hatching/crosshatching, was sourced from a book as it was the assignment to copy a drawing that used crosshatching (and it does have errors in proportion when analyzed against the original, I can dig it out if you feel the need to check for yourself). I ended up drawing it upside down though because I am left handed and wanted to keep the hatching in the same direction as the original and it was easier to do that by turning it upside down, much to the amusement of my friends. It is graphite, on a sheet of 22x30 inch Somerset paper and took about 4-5 hours (we were expected to spend between that amount of time on our homework assignments).
And the second was sourced from a low quality jpeg, which was further reduced in quality by my really low quality printer back then so some artistic license was used to fill some of the details. Being from a photo and because it was for a life drawing class it was not well received by the instructor (he actually only liked the hair) but I, and thankfully a few others, couldn't find anybody that had enough free time during that part of the semester to sit for a 20hour sustained drawing. It is also 22x30 inches but is charcoal on a piece of natural white Stonehenge paper, a type of paper I had not used before for charcoal and it proved more difficult than I expected to blend the charcoal and didn't get the shading I wanted and the drawing doesn't have the depth that I would have liked it to have.
And well because I missed one class, and forgot to bring in the assignment I was asked to do to make it up (which only took an hour) to my final critique so I ended getting a Marginal Pass which equates to about a D and completely wrecked my GPA. The reason being that it would be unfair to the other students who did all the assignments (and didn't accidentally forget to bring one in), but I was given a commentary signed by the instructor who at the time was also the head of the drawing department that stated the grade was because of the missed assignment and not a lack of skill because normally getting a Marginal Pass prevents you from advancing any further in that discipline. But I never bothered to take any more classes in drawing because at that time I had already been booted from the same class, but with a different instructor, the previous semester for 'creative differences' (it was more that we just got on each others nerves, and when I was late for two classes by about 5-10 minutes(of a 4 hour class) so she marked me absent, and so when I missed a class without what she considered a legitimate excuse she considered it equal to 3 missed classes which equals automatic failure under the attendance policies, so she told me to get out because it was still a few days before the drop date so I could avoid getting the F but still lost the money for the class. So if you decide to study the arts take the time to research the instructors and make sure you are going to get along, because art is entirely subjectional and if the instructor isn't going in the direction you want you aren't going to be very happy. Although in my opinion the best instructors don't force any style on you they just teach you the technical skills and let you develop on your own, and those are the ones I made sure I had from then on.)