Help?

Ok.. i just want to know what you would do in my position, im not really asking for proper advice just back up.
My nan has a terminal illness and we're not sure how long she's with us for but because i'm so preoccupied with her, i'm pushing away my fiance.
He's trying his best to be there for me but in my grief, i snap at him then cry on him, then snap at him, then cry on him... you get the picture.
At the moment, im doing my best to show him i appreciate him being there for me, and bless his soul he understands and all he asks is i come to him when i need a shoulder.
But what would you do in my position? Would you have the uncontrollable moodswings or am i being a bit out of order?
=(
*Gem*

The uncontrollable moodswings are completely understandable! He'll have to deal with you and what you're going through.

All three of you have been a huge help, i sat down with him and i talked to him about last night and things are a lot better at the moment. (Even if it has only been a morning, lol) But i have a good feeling about it now. Britt, it's nice to know i'm not the only one who does this. I don't feel so alone now. Ellie, thanks for letting me know it's normal and can be controlled. And Dead Soul, cheers for telling me guys can be understanding too =)
Thanks everyone. xx