I'm in the process (procrastinating my arse off!!!!!) of applying for disability, and I can totally relate to your feelings. I even feel a horrible sort of... embarrasment? shame maybe. And I feel like I don't "deserve" it. A sort of "why should I be paid not to work when others have to work?".
If you've been approved though, it means you NEED it and you deserve it. I understand you feel guilt, but you also shouldn't, because you're entitled to the benefit, and it's there exactly for people like you who need it. If there was a choice between this and being well enough to work I'm sure you would take it.
Hope your feelings have settled a bit. You need and deserve the benefit x