Here is my explication. Two or three lines are cited followed by analysis in brackets.
Is it for fear to wet a widow's eye
That thou consumest thyself in single life?
(Are you living in an unfulfilling relationship just because you don't want to hurt a woman's feelings? You only have one life.)
Ah! if thou issueless shalt hap to die.
The world will wail thee, like a makeless wife;
(If without children you die, the world will mourn your loss like a widowed wife.)
The world will be thy widow and still weep
That thou no form of thee hast left behind,
(The world will be your widow and mourn your loss even if "no form", ie, children, have been created.)
When every private widow well may keep
By children's eyes her husband's shape in mind.
(Those with children can look at their offspring to be reminded of the loss of their spouse.)
Look, what an unthrift in the world doth spend
Shifts but his place, for still the world enjoys it;
(An "unthrift" is one who does not watch his money. It doesn't matter to the world; the world enjoys his presence.)
But beauty's waste hath in the world an end,
And kept unused, the user so destroys it.
(But youth and beauty are temporal. Like money, they will have no place or merit after death.)
No love toward others in that bosom sits
That on himself such murderous shame commits.
(We are selfish beings. It is only the self that is hurt by not enjoying life when we have it.)