Not your fault, but your comment made me subtly sad that I haven't repaid the same sacrifice and commitment from my family with as much as they deserved. They too worked very hard to provide and give a good life for me, and through naivety, youth, inexperience, laziness - I pissed a large portion of it away.
I try to do better now, but I think I'll always carry some personal guilt over that. I can't fix the past, but I can work harder and try to correct some of my mistakes.
edit I neglected to note that you mentioned your dad to have passed. Take reassurance in that a brief comment on the internet, I think you've done him proud.