There's a balance, isn't there . . . between thinking on the one hand that you are not worthy of someone's love, and on the other, of taking it all for granted.
In my humble opinion, it is worse to take her love for granted, that to feel a little unworthy of the love you receive.
To love a woman properly, over many years, she must be desired and loved, pursued and won many times, over and over, through your life.
If you're lucky enough to receive the love and affection of a good woman, don't ever think that it is something that can be taken for granted. If you neglect and discourage her for long enough, you can turn the fire of her love to ashes. It happens all the time.