If you don't feel comfortable telling your sons what you're reading, why not just tell them you need some time alone to clear your thoughts and rest after a long day's work? They should respect that and leave you alone for 30 min.
About not having the motivation - personally I feel SA is a terrible thing to suffer through and is something that I want to be free of ASAP. That's more than enough to keep me motivated.
How badly do you want to be free from SA? I don't know about you, but you need to convince yourself that it's worth putting in the time everyday, because it will work if you go through this program and do what it recommends.
Also, it's not silly to want to take care of yourself and want to get better. That's probably just an ANT that you need to get rid of.