So I F'd up and I feel really down... help please

Basically I started coming on here maybe a month ago, and it was really helping me. Thanks to anyone that posted to me. But I stopped coming on here, I got very depressed again because I constantly feel as if no matter how much I do it's futile because there's a whole other list of new things that just get piled on top. It would probably help if I explained, my dad passed away 08/05/2011 and I've had to deal with all the legal stuff, I was 19 then, I'm 21 now. I was not at all ready for the responsibilities of a house: The tax, the bills, the generally keeping everything together. From then until now I've been under tremendous stress and pressure, I had to sell the house my dad left me- and the home I'd lived at since I was 3- and move house. When I moved, and I found this site with all you amazing people I was finally at a point where I felt I could get through this. But of course recently things have gone down hill again, and I have terrible trouble dealing with that, I always have because I've always felt as if my life doesn't get to get better, it'll level out and be okay for a bit but then it just starts falling, cascading full pelt down and down and down and down. It might not even be true but I've always felt like that, so even when things have been good I'm always just waiting for the carpet to be dragged up from under me, all over again. SO to cut to the chase, I've been picking AGAIN and I feel honestly awful, and I hate myself and my weakness, and my stupidity for not coming on here. I'd even be thinking as I pick, 'I shouldn't be picking right now, I should be posting'. EVERY TIME I've had a moment alone in the passed few weeks I've picked. I've had some BAD, by my standards, picking sessions on my arm, where I've sat for hours maybe 2-3 or even 4 HOURS just picking away at my arms, I have KP so I pick at the old scabs and the horrible little pimples that come up anyway. I've not done SO bad on my legs, only maybe doing a few bad picking sessions on them, and I'm not letting go of the fact that they still look better now than they have done for 4 or 5 years which is an ACCOMPLISHMENT, BUT!!! I still can't wear shorts or skirts, or get a spray tan, go to a spa, go swimming and it's so DEPRESSING. As for my arms, I can't even get them out at all, I want to leave them alone sooooo BAD I hate it!!! SERIOUSLY I am just at my last straw I really think if I can't stick to this I never will be able to because I've tried and tried and tried and tried... to stop this and I just can't. It's my crutch, my vice and it's ridiculous but it's the one thing that distracts me from the stress and helps me, it NEEDS to STOP because it creates stress. When I pick badly on my arms, I break out on my face because I am so ashamed. My KP started it all, I remember when I was a child, another child said to me 'eurgh, what is that on your arms?' and that's where it all started, the mission to get rid of this rash by picking out 'the infection'. BUT even when I found out later more about KP, I didn't stop, I still can't stop and I WANT TO SO SO BADLY. I would welcome and thanlk any help right now I really would, I'm at the lowest I've been in a while. When I first came on here I wanted to be clear enough to wear short sleeves, and skirts by October 20th but that is merely a dwindling dream now, ANOTHER date down the drain. I want skin to be proud of, I just want to be BETTER tomorrow than I am TODAY and so on. PROBLEM, I don't think I can do it anymore, I've lost faith in myself and I neeeed it back. Love all you guys so much thank you xxxxxxxxxxxxxxxxxxxxxxxx Jo