Whenever I feel like that (or more likely when someone else feels like that, since I have troubles getting out of that "my failures matter more" mindset too), it's good to look at others. Not the ones you compare yourself to and feel bad about yourself, but those who have nothing. I'm not saying "others have it worse than that", and thus neglecting you. This is something different. Think about someone who has absolutely nothing. Look at someone who is absolutely miserable. If you don't know anyone like that, you can imagine one - it's not like you would be making up things that don't exist, since misery is everywhere.
Now, think of that person, imagine you're looking at them. Are they cold? Are they ashamed? Do they hate themselves? More importantly, what do you feel about them? Do you hate them? Do you think the world would be better off without them? No, you have compassion. Here's the trick how we know that what we feel about ourselves isn't right or true, it's just in our minds. That person made you feel like you want to help him/her, that they matter. Why are you so different, then? You're not. You matter too.
There were long periods in my 20s when I lived at home. Sometimes I was between jobs, sometimes my relationships went wrong with the people I lived with and couldn't afford the places on my own, and sometimes I was just feeling like a coward, sitting in my comfort zone, afraid to do anything. My cousin was like that too. He's over 30, and he just moved out and got some part-time job. This happens everywhere, you are definitely not as alone as you think. In some cultures people share that one home, all their lives, and it's considered honorable and normal. I personally think that we worship "independence culture" way too much. We don't have real communities that much anymore. Everyone is supposed to just go off alone, work in a cubicle, get back to his/her empty apartment and fall asleep, dreaming of a slightly bigger cubicle and a person to share that apartment with. Not to say that I don't appreciate people who make things happen by themselves - my parents surely did that - but in the end, even for them, it was about getting a home where they could raise me.
And don't you worry about "using" your dad. Everyone uses connections, and a job is a job. Every one of my family members or friends the same age as me or younger, at least most of them, have at some point had jobs (full- or part-time) they got with connections. It's a matter of us helping one another, to truly feel connected, and I think it's good. Family should mean more than a name.
Your hallucinations and psychotic episodes. That wasn't you. And if it was, your reasoning was hindered by your illness. So why do you call yourself a monster? Do you think others don't have dark sides to them? You just told me yours, so I'll tell you mine. Once I was a drunk. Not because I found it fun, but because I couldn't cope with several issues. One of the issues was my then girlfriend, or rather what had happened to her in the past. There was a disgusting crime committed against her, and I knew the people who did it. Nothing came out of it in court. I wanted to kill those people. I wanted to kill every last one one of them. I would fall asleep imagining myself breaking into their apartments and murdering them. I fantasized about torturing them. I even thought about: what if their families (they had ones) were there? I thought several different scenarios. I was filled with hate, so damn filled with it that it tore me apart that I had trouble sleeping because of it. Obviously I never made serious plans to go through with it - thank God - but the hate was real. Does that sound christian to you? It doesn't, because it isn't. If you called yourself a monster, what am I? The monster captain? What I felt, what I wanted, was sick and wrong. And after all that, I believe God loves me just as much as you. Not because I deserve it, but because He is God, and He gives His grace freely, so we would look up to Him and thank Him, and try to love one another in the same way. It is true that none of us can boast, and it's liberating.
You can turn those thoughts into something positive. It rarely happens like turning a switch, but God's ways are incredible. And I think you're not that far away, you just need to get over the worst. You can turn hating yourself into healthy humility. You can turn all the things you are ashamed about into advice for people who suffer from the same things. You can turn enduring these times into patience. God will always be there.
Hope my ramblings didn't get on your nerves.
