nidal

The problem is not the addiction ... I think you feel that "you did not expect him to be this way" ...
OK. now you was clear with him about the history of the breast cancer in your family... and he did not tell you about his addiction because he thought that u will not marry him .
you just need to tell him "you can not live with addict person .." and explain to him ..WHY ?

1- Ur expectation was wrong.
2- he will kill him self
3- your child will born in bad environment and you will not be able to take care of the child
4- addiction is dangerous disease more than cancer even... because it is ur choice and not ur fate.
5- tell him "I want u to be the most beutiful and strong husband" in all ur life aspects.

this type of discussion is very important ... probably he knew these facts by his unconscious mind ... but his real mind is absent.
this type of "EXPECTATION TALK" .. will trigger him to change or be quicker in the change.

about you are "moody".. I'm sure not. since you have a big shock and it seems to me you are ideal person who like the energetic life and you want ur husband but without his addiction ...you are very shocked by the "dream" ... that is not "my dream" ... well .. this is the life ..If you so brave ..you can change your partner and stay near to him to leave the addiction.. do not be desperate ..
Love is not just words .. it is an action ... so ..where is ur love ?
if he loves you ... he will try to change ... but you must change your attitude to him...
praise him about good things you share together... and plan for ur future .. let him write the dreams you like to reach together ... he might write "NO ADDICTION" ...HELP HIM to write it if he can not.
also hang this sheet in ur bedroom and in the kitchen ...so he can keep it in mind...
make him to feel love with you ...hug him ... kiss him ... praise him with a shower of nice words ... send him a letter of appreciation of his cooperartion with you.

good luck.
Nidal