First of all, welcome to DP! I'd say it sounds like you have a pretty nice job for not having any education in the field (or at least that's what it sounds like). However, I feel like they should understand if you aren't able to implement some of the higher end designs and web elements, after all the average salary for a web designer is around $70,000 - if they expect you to perform at that level but are only paying you a fraction of the average, that's a bit ridiculous. Of course I don't know the specific details of what they're asking, but I'd just let them know if there's anything that you can't do, and let them know you're willing to work on learning how to implement those things. I work in IT myself, so I know what its like to have nobody else know what type of work you're doing, fortunately in my case they always assume my work is a lot more difficult then it really is