Feeling down

My birthday is a month away. I'm planning a bbq, like just some beer and burgers. I invited my mom, dad and two sisters. My one sister told me she can't make it because of work but then told my mom that it's because of my hubby Mike and that she doesn't like him. I told my mom that it's not about him and that the party is about me. My sisters never make an effort to come to my things ever. They always expect me to go to there's and I always have. I didn't have the money to go to there's and I still did. I went to my sister's 30th birthday, I went to her Bach party, and I went to her wedding all in the same year. Every time I ask her to come to my thing she said no. I figure the next time her and my other sister plan something, I'm not going. Both my sisters treat me bad. We found out my other sister was camping 20 mins away from my house and she never even dropped in to say hi. She's from out of town. I'm just not feeling important. I guess the important people will be there. I'm thinking of cutting all ties with them and just being with the people that treat me right. I'm kind of embarrassed because my hubby has to invite his friends and family because only my mom and dad would be there. I haven't made any friends yet