I second LegoMom3's response. I may be reading into your post, but it sounds like this trip is warranted. You say things like "I think I had 3 weeks of peace and that is it" and "I am at the end of my rope---all of my enthusiasim is gone." Both indicate to me that the trip has to take some priority, for your immediate family's well-being, your DH's and DS's needs and your own emotional health.
And I hope I'm not speaking too far out of turn, but it sounds like you might want to use this time not only to find appropriate short-term care for your mother but also to start looking into longer-term care options. If her needs are increasing--and it sounds as if they are--then now is the time to address the situation. I know we don't like to think of this, or at least I don't, but our parents get older and they can then depend on us more and more. And that can be exhausting. So I believe you'll want to look into getting some relief from your situation as the only child and (potentially) the only adult caregiver. I'm not necessarily talking about assisted living situations or nursery homes, but a variety of options. Does she have insurance, savings, etc., to pay for health care? What about your family's financial situation? How about your mom's relationships with other adults, like members of a church or another community organization? Does she have a circle of friends to help with her emotional and intellectual needs, and perhaps her physical ones? (If no to the last two, then your mother needs to work on gaining those important social networks.)
And, perhaps most importantly, have you had these conversations with her? If not, it sounds like it's time to start.
I'll be thinking of you and hoping for the best. In the meantime,
