Jimmy, I'm in the same position -- and my solution is I've just got used to it! Well, not exactly... As I'm sure Oprah has said at some stage, you have to undertake an activity/vocation first because it's your "passion" (hate that word in its modern sense) and you can't not do it, and for the innate satisfaction it gives you. Any sense of external success deriving from from a book is a bonus largely dependent on the amount of publicity put into it at the front end. My last book had literally none -- and my only ongoing satisfaction is that it has been bought around the world by the 30 most intelligent, searching, resourceful and literate people there are! Previous books that I was able to give some very limited promotion (by myself, without taking away precious writing time from myself) sold in the hundreds ans are still selling steadily because they have specific readerships that I was able to target. May I ask what your genre is?

I hear you. I've published 5 novels and written a 6th but it seems so pointless to write if it's not going anywhere.
I've had some good fortune (sold movie potion and over 1,000 of one title to the Department of Science, but I absolutely understand what you're saying. My 6th one is unpublished because there just seems no point.

My feeling is that I need to write for myself. If I'm happy with my efforts and growth as a writer, it really doesn't matter to me what others think. I do, of course, want people to read my stories and enjoy them — though I've done no publishing, self or otherwise, yet, so it's limited to a small group of friends who've read my writing — but my primary motivation is to write for myself and to enjoy the process and be pleased with the finished work, and to improve continually in the craft. That doesn't put dollars in my pocket, though, so if it's your goal to make a living as an author then your motivations for why and how you write may differ significantly and you probably need to learn a bit about marketing yourself to your target audience.