Unproud parents

I got 20/40 on my maths prelim and my teacher said it was encouraging. I was so happy with this result because I thought I would fail and many in the class got like 10 and below on this paper. I told my parents and the both said "that's shit" ? Then my dad sat saying that I'll never get into uni with that (even though this is a national 5 level and not a higher which I'll do next year) am I over reacting because it seems to me he's being a total dick and expecting too much of me and I'm really upset that he said all this stuff practically calling me hopeless. I tried justifying that I have a bad teacher, that we aren't taught how to answer questions properly and that all of the other school in the county have 6 periods of maths a week and we only get 5 since we're a catholic school and that 6th period is wasted on a second RE lesson. This course is also very hard as many failed last year too. But I feel so crappy now and think I'm doing ok in school but am I?