I grew up in a very *****y home environment and cut contact with my parents. Despite this I got straight A* at A level/gcse (although I don't go to a good uni since never had confidence to apply anywhere good).
I flat-out despise most lower class people for their incompetence. All my brothers/sisters dropped out of school young, and looking back on it it was clearly my mums fault. I've cut contact with my parents/family now.
The worst thing is that I absolutely cannot stand single mothers. I was in an argument with one in Tesco a few days ago (it was about queue pushing) and when she started using that for sympathy I had an incredibly strong urge to beat the crap out of her for her incompetence and had to walk out to stop this. I think this probably stems from how horrible my time at home was with a single mum and I've generalised it to all of them.
How do I get rid of these feelings/learn to be more accepting of people?
I think you could do with putting your self in the position of the "incompetent" and consider what could have lead them to where they are no one wants to have a *****y life position but sometimes it is forced upon people. Imagine what being a single mother must be like you have to raise a child another ****ing human being a life in and of itself and you have the pressure of ensuring they don't grow up to be a psycho and at the same time they have to work a job that gives them enough money to actually support not only their own life but also again another smaller human that can't fend for itself. The cost of childcare while they're at work is astronomical. Now just from my point of view that isn't incompetent if anything that's very competent to juggle bills a job and a child.