When indie authors come to me and ask "Should I just give up?" it's hard to answer. Without knowing a lot of the history of the book or what the author has done, it's a bit like trying to diagnose a patient you've never seen. There are, however, some tell-tale signs that you can breathe new life into your book. Here is a list of thing you can try before throwing in the towel. They might just help improve stagnant sales.
Publishing a first book may be a thing on your bucket list, and if that's the case, and you don't want to think too much about the money, then don't. But if you're serious about earnings and have your sights set on becoming a career writer, writing your first book is not unlike standing at the threshold of a new galaxy.