Your situation is very similar to mine. I hope your A-levels work out alright. I'm really angry and upset. I blame it all on my drama teacher.
While I don't know anything about your situation, I also blame(d) my teacher since he didn't really teach anything properly and kept me under the impression that I was on track for an A or A*. Although I do understand the difficulty they had because Engineering was sort of the oddball course of the DT department. It was a different exam board from all the usual DT subjects like Systems & Control, Resistant Materials, Textiles etc. which they knew how to teach.
Not to mention that it was done by very very few schools. I'm not entirely sure why my school even offered it. It was definitely a very stupid moment in my academic career when I decided that Business Studies was boring and switched to Engineering two weeks in. xD Hope it works out for you. Are you sending it for a remark?