yep, sounds similar for me 2 about 6month ago, never thought i was meant for this world either, i still dont. I wanted to kill myself everyday and had to cut everyday.
You sound like there is a lot of things that you need to deal with in your life at the mo and the intensity of it all is difficult to manage, thats the only way i can think that you have a good life but yet hate it. I am 26 tomorrow and i am still struggling, i stopped a few months ago but valentines day meant i just had to cut as i new no other way to deal with it. 4 me i know why i do it, feels good obviously, makes me feel worthless and because i know no one else cares what i do (family excluded), i can do what i want to myself because i dont matter, a lot of spite in it for me and it makes me happy as i know i cant feel any worse than resorting to doing it.
You are not strange for doing it, there are plenty of us out there, everyone has their own way of coping with life and a lot of people dont understand my way.
To make me happy i try to see things in a different way, if i can see people that are happy it makes me smile as i think at least someone is happy, they have what i want, I have no idea if i will ever be truly happy again but i live in hope that i can feel like i once did before. I just try and cope in the meantime and try and keep myself busy, playing a sport helps me and beer

oh and keeping a job, if i lost my job that would be the end of me
Im sorry if i am a bit off the topic or even wrong, i have not spoken to anyone about me before so i dont know what others think or why they do it etc etc, i also dont want to sound patronising in any of it as its not meant that way. I hate people telling me what to do.
Sorry 4 rambling on, i wish you all the best and hope you find what you want/need too, take care x