Kian
Your wife has a point, it must be very tough living with your parents, even if it is cheaper, the psychological aspect of living in another womans domain is a very heavy burden to bear, if you had to because of economical circumstances I understand, but you should have done everything you can to get out of your parents home as quick as possible, they are your parents, and though you might feel quite comfortable going about your business there, it must be a private hell for her.
Waitering can bring in an average of R200 - R300 cash per shift (per night) sometimes much more, depending where you waiter, it really is a good suggestion.
Selling curtaining, in this age my friend ?, curtains are out, everybody that can afford it, will rather have blinds, I have no idea why you're selling curtaining, it's just not a good choice in these modern times.
My daughter comes from an upperclass home and is waitering her butt off to make a living, as she simply can't find a job, she's living in a students residence and doing everything she can to be independent from her parents.
Your first priority is to find a job, sharp-sharp and to let your wife understand that you will now do everything you can, to get away from your parents, if you don't act fast, your parents and your wife and thus your child will all soon be very miserable, and it seems as if you're squat in the middle of this situation.
Please Kian, do what it takes, take any job that will immediately put some cash into your situation, you cannot procrastinate any longer.
Best of wishes, I hope you get lucky with a job and that taking immediate control of your situation will prevent the impending explosion.