What can be done for someone who has committed suicide?

Salaamu-Alaikum.
I hope you don't mind me asking this question, but my cousin committed suicide two weeks ago because he could not handle the exams pressure, according to the note he left. The family all know what he has done is terribly wrong and un-Islamic and the consequences are stated in the hadiths of our beloved prophet. What I would like to know is that is there anything that we can do to help him in the hereafter? Is there anything we should be doing to his grave? basically, what should his family do to help themselves get over the terrible situation and help him? Please help!
Jazakallahulkhair .

Praise be to Allaah.

We ask Allaah to compensate you for this tragedy and reward you for your patience. We have already discussed the issue of suicide in brief under question 373, section 5. As regards what you can do for your deceased loved one: if he was a Muslim who died without having done something that would put him beyond the pale of Islam (such as denying any part of the religion, making fun of some part of it, or totally neglecting Islam to the extent that he did not learn or do anything, etc.), then you can do many kinds of good deeds that may reach him (see question 763 for more details).

May Allaah take care of us and you by His Mercy.