<human>: Provide a brief overview of the text.

Hi everyone!
As the title says, my friends who I have known for 2 1/2-3 years are acting cold and distant to me :( and i really want to invite them to my birthday party (turning 18 tomorrow, yay :D) because we have so much fun! 

Just some back story, these 2 girls are like the sisters I never had! Always caring and helpful and when we go out we have the best time ever! In fact I went out with one on Sunday and she seemed so excited! I messaged them (not about the party) yesterday and they just ignored me, they seemed quite irritated when they got back and I'm debating if i should just stay home tomorrow ( yes I have other friends, but like going out with them the most). I haven't talked to one since end of May due to the massive amount of work and i think she understands. 

So in conclusion I would like to know if i should invite them tomorrow and what I could have done to make them angry.

Thanks in advance :)
<bot>: Long time friends seem mad at me out of the blue and i want to invite then tomorrow to my birthday but scared I'll be annoying.