Horrible Prac Demonstrator

Had a super long day at sch today... & a not so good one =(
ok, it started off pretty well, i made it for almost ALL the lects hee.. den had PRAC again in the arft =/. it WAS pretty alright at first, the work was easy cuz it was just computer stuff, den after tt we had to do another protein assay, which IS easy cuz we've done it like 3 times already. BUT, we got our performance marks back today.. &.. mine was BAD.. quite BAD. i reckon i got like the lowest out of my group. i felt so cheated when my demonstrator told me my marks & gave me his 'assessment' of my practical skills. basically he said i was "not clear on your work in the first 2 pracs.. never seem to rmbr to close the lid on the spectrophotometer.. asked u qns but u can't ans, which just shows that u're not prepared. but u did well in the last 2 pracs, can see that u put more effort into preparing for the prac, & understand the work." GOSH. so does that mean i am GOOD or LOUSY? i guess it has to be lousy, cuz he gave me such low marks. & cuz i got good marks on the last 2 prac reports, he was so darn sarcastic & said " u did so well in the last 2 pracs, i was even thinking who did u copy from!" OMG, when i heard that i was so darned pissed! even more den i oredi was! FIRSTLY, i DID NOT copy from anyone! it was more like, pple copied from me! & also, he judged my performance based on the last 2 pracs, when he ASSUMED that i didnt prepare for them just cuz i couldn't ans the qns he shot at me immediately. & like, half the time I was the one who had to advise my partner on what to do in the prac, & to think she ended up with more marks then me, & also that my demonstrator actually thought that she knew her work more then me!.. i am NOT jealous of her marks, but rather, i just feel so cheated & so 'yuan wang' yes, perhaps i didn't prepare enough, perhaps i just don't have the fast thinking abilities that he wants me to have.. sigh.. life's unfair.. =(