I believe mature love begins with the individual. By that I mean a person who has "self-love" and views their marriage as two (whole individuals) coming together forming a loving union understands that marriage is an "at will" arrangement. When it is all said and done. A commitment is only good for as long as both people have the same goals for the marriage and (agree) on how to obtain them.
A healthy person would only want to be married to someone who (wants) to be married to them. They understand love and affection are given freely. These are not things you negotiate for or demand. Although it's romantic to say or hear such things as "I need you as much as the air I breathe...etc" It is not emotionally healthy be that way.
Once you have given your best to a marriage or relationship and the other person decides for whatever reason to end it there really is nothing more you can offer. Sure it will hurt like hell but begging, pleading, and fighting to keep someone (who does not want to be with you) is an indication you don't love yourself. Personally speaking I'd rather be (wanted/desired) by my spouse than to be needed. The word (need) implies a person is not there out of "choice". If marriage is work it should be your "dream job" and not some job you are holding onto because you "need the job". One man's opinion! :-)