It's common for a person to have self doubts. The question is how deep do these doubts go? Many of us don't have enough self awareness to answer this question. As a therapist I find that many people have some negative beliefs about themselves, and often don't consciously recognize this fact. I help clients explore what negative self beliefs may be under the surface, and assist them to recognize and let go of these beliefs.
When a person feels "not good enough/inadequate" on some level, he/she often looks to someone else to make them feel good. But no one else can consistently boost up their spouse enough to erase those deep self doubts. A spouse's love is great, but they cannot "plug the holes" of self esteem in the other person.
In the "looking for someone else to make us happy" we get disappointed, and even angry at our spouse because they cannot do it. Also, if self esteem is poor it's difficult to be emotionally close because we may be afraid to let someone see us "up close". We get defensive and can misunderstand our spouse. It's harder to clearly hear our spouse's feelings and point of view, because we get stuck in our own emotions.
Liking one's self is distinctly different from arrogance, which is a cover up for lack of genuine self esteem. Real self esteem is flexible, kind, humble, and is essential in a mutually satisfying relationship. One can then be open about his/her feelings, open to the other's feelings and point of view, in other words, emotionally available, a fundamental necessity for a satisfying marriage.