Hi notmrsbrightside, I'm sorry your husband is finding it hard to be by your side in this and it may seem to you that all your efforts have been counting for very little. But just remember that even if your efforts weren't recognised by your mother or sister-in-law they had to have made a difference in whatever way to what your father-in-law was going through (which I'm sure at times wasn't in the least bit easy) and in offering a really respectful/caring testiment to him afterwards. And even if you were doing things for your mother and sister in-law sometimes that at least gave them more opportuntiy to focus on your father-in-law as well. So please allow that to give you some comfort, in that what you did really did matter and you did do something/s really significant and meaningful
As for the relationship with your husband..........well I can see you understand that things might be quite difficult after his father, it's got to be tough. But maybe see if some of the grieving you can do together?? In some quieter moments maybe talk about memories........the better and the harder times with your father-in-law and share some of those feelings. Try not to talk about any problems with your mother and sister-in-law at those times.
And just try to make "a place/places" in your day's where it's just you and your husband, it's not about you, your husband, your mother-in-law and your sister-in-law in the relationship......it's just you two.
Sure he might have to respond to some "challenging" requests from his mother (which sometimes he might not like either) but if you could see some of them as unavoidable...........and try not to let it effect what you two have together as much as possible.
Obviously talk to him if things are really bothering you.........but maybe a balance???
And for your birthday........I completely understand how you might feel really disappointed with the plans falling through but you can still still fit in something really special.......just the two of you for part of it maybe??? Sometimes the simplest things can be the best things???
And you know maybe you could do with some more "outside" support as well??? It can be helpful to have someone "outside" of things to use for support or as a "sounding board". I really sorry you're friends seem to have let you down, but maybe someone else??? And there's always us!!!!
Don't go thinking that your problems always have to be secondary........they matter too!!!!

Alison