I went through a similar experience about a year ago. It's all in my post history.
I began to miss meetings and received phone call after phone call along with numerous elder visits, even though I had some serious family issues to deal with. I was missing due to family reasons, not because I wanted to leave. Well, things came to a head and I decided I'd had enough, it was emotionally and physically exhausting.
My family and former friends now shun me, yet I've moved on to a better life. It's a spectacular feeling once you leave!
As far as your guilt regarding gifts. I understand why you might feel guilty, being raised in an organaztion which constantly makes you feel like you aren't doing enough. You need to do what is right for you, but remember, if you leave all those people who gave you gifts will not speak to you, ever. It doesn't matter how you try to leave, it will only matter that you left to them. There is no honorable way to leave the org. You should not feel guilty for leaving, you have done nothing wrong.
PM me if you have questions about my story, it took me about 3 months to get over it and break free.