Linda and I, over our fifty years of marriage, have met with many premarital; and marital couples. A percentage of these meetings concern couples who are talking about ending the marriage.
One resource we draw on is Gary Chapman's book One More Try: What to Do When Your Marriage Is Falling Apart.
Here's some wisdom from the book, which Linda and I share (as do many marital counselors).
"It has been said that unhappy marriages consist of unhappy people. You may not be able to change your spouse, but you can change yourself.
Marriages fail for three primary reasons: lack of an intimate relationship with God, lack of an intimate relationship with your mate, or lack of an intimate understanding and acceptance of yourself. It is the last of those that we shall explore in this chapter. One might think we would begin with our relationship to God, but the fact is, one’s relationship with God is greatly affected by one’s self-understanding. This time should be used as an opportunity to rediscover your own assets and liabilities as a person and to take positive steps in personal growth. Even if you are not separated but are struggling with a marriage in crisis, it is possible—indeed, necessary—to look deeply at yourself and begin to make some changes." (P. 41)