My friend, YOU sound like the mature, thinking, and loving Christian, in the situation. You can, usually, never go wrong with applying those qualities. Your getting frustrated, and "losing it", is NORMAL. Remember, YOU are the one who is being JUDGED by them, and you are the one who is not receiving true love from them.
Unfortunately, your parents are in a cult, that does not allow critical thinking, in fact, critical thinking on ones own, SCARES THEM. Your parents, are most likely, fully indoctrinated, and completely under the WTS brain washing control, and its ashame.
For what its worth, the toughest part for you, is probably because you live under their roof still. Everyones financial situation is different, and not all can, but i can guarantee that if you were able to move out, things between you guys would get better, hopefully.
I dealt with a similar situation with my father, when i was in my early 20's. He in many cases, and not just concerning JW/spiritual things, was very judgemental at certain times. He would sometimes, talk down to me, belittle me, and berate me. We would on ocassion, although most of the time i tried to be the "better" person, get into frustrating screaming matches. Eventually, i found that the best course for me, was to just move out, and get my own place. I went on to live my own life, under my own roof, and with my own rules. I went on to become successful in business, and have my own family, and children.
After moving out, and paving my own way, my father tremendously "softened" his attitude towards me. I cant speak for what for him the catalyst was. I dont know if it was guilt, or becoming, eventually, proud of me, or just realising the error in his ways, but we started having a much better, and more loving relationship with each other. Today we are closer than ever.
Sometimes, things just take time. Continue to think for yourself, like you are. Do for yourself, and continue doing well at work, and progressing from there. Sometimes parents, simply dont respect their childrens "wisdom", until they get older, and maybe realize, that their children WERE wise all along, and ahead of their years. I have a feeling, this may be whats going on in your case. Try to give things time, and continue to flourish, and do well for yourself, and things WILL fall into place.