Q n A : His father wants him to marry his cousin who is close in age to him

Praise be to Allah.Note
that is is impossible for things to stay the same forever. Glory be
to the One Who changes His slaves’ circumstances and directs them as
He wills. Our advice to you concerning this problem is first to think
of marrying the relative whom your father has suggested that you marry,
regardless of the   previous knowledge to which you refer. 
If she more or less has the qualities that you want in a righteous wife
and she does not have any bad quality that you think you could not put
up with, then marry her. Perhaps Allaah will decree much good for you
in that, and your honouring your father will be the cause of happiness
in your marriage.
 
But if there is an obvious fault that means that you could  not
marry her, then explain that to your father and try to convince him
that forcing a man to choose a wife whom he does not like could cause
the marriage to fail and could also cause harm to that girl. Advise
your brothers to try to honour your father and keep in touch with him
so as to strengthen the family ties and put right what has changed.
And Allaah is the Source of strength.