My first marriage will be my only marriage.

Some suggestions for you :
Marriage is the beginning of love for your spouse, not the result of it.
Marriage is neither heaven nor hell, it is simply purgatory.
Marriage is like a long conversation that always ends too soon.
Marriage is three parts love and seven parts forgiveness of sins.
Marriage is a great institution, but I'm not ready for an institution.
Marriage is a bribe to make the housekeeper think she's a householder.