Psychology Today - 5 Strategies to Help You Move On

It’s hard to get unstuck from a relationship or job. The alternative is worse.
Published on September 11, 2014 by Peg Streep in Tech Support

For all the faith that we put in grit, the truth is that persistence actually tends to be the default position in humans, thanks to our hardwiring. Letting go of someone or something we once deemed important or valuable is much harder than hanging on.
If there’s a single, most common mistake we make, it’s staying in a job or relationship long past its expiration date. Try this exercise: Compare how many times you’ve heard someone say, “I’m sorry I didn’t give it more time," with how often you’ve heard, “I should have gotten out ages ago."

We are creatures of habit, geared to keep going and second-guessing. We know we need to get a move on but we hold on for a myriad of reasons—habits of mind, over-optimism, choosing the known over the uncertainty of the future, fear of making a mistake, and just plain inertia.

A book that helped me was The Language of Letting Go//Daily meditations…by Melody Beattie.
Bought this book years ago for other reasons, but the lessons seem to cross over into all kinds of relationships and situations.