it sounds like you're having a pretty sucky time trying to figure everything out and i'm sorry. sometimes it takes a little time to find your passion and that is completely okay, if it's not right, it's not right.
and you won't be 'wasting' a degree by not doing it. if you tried it, learnt about it and went for it whilst you thought you liked it, it's not a waste at all. it's okay to change your mind. life isn't all straight roads. it's confusing sometimes.
i believe that if your passion is with a trade or you want to do trade, just do it! even if it's not the most money in the world, even if your parents don't want it. try your best and give it everything you've got. your mental health and life is yours to decide. not anyone else's.
and again, if you try a trade and discover it's not for you, it's not wasteful or disappointing. it's just another step in discovering where you want to be in life. and that's okay.
i'm not too good with this 'advice' thing. but it seems as if you just need to follow your heart in this situation and forget about the outside problems (i.e family, money etc.) if you love it enough, you can make it work...no matter what it is.