True,
what you feel is very normal with your brother passing away and your sister going into hospital.
What you can do as you are here in Doha might be more and much better then if you were back home:
1) you can financialy help and support your brothers and sisters back home.
2) you can pray to God to put your late brother ( and parents )in heaven
3) you have good friends all around you here praying with you and supporting you.

Heads up
Work hard
may God be with you
You will be suprised how things will eventualy work out for the best.