So upset

I am a military spouse, I have lived in different countries and states from my family for almost 9 years, i sometimes get to see them once a year if I'm lucky. My sister flew to visit me this last week and today i had to take her to the airport to go home. I have done nothing but cry all day. I'm sure most of it is hormones, but i feel so lonely now. Last time i saw her was 2 years ago. I also have no friends where I live so having her here to just sit and hang out with me and my kids this last week has been amazing. Sorry for this mostly pointless post. I just needed someplace to post my feelings. I've felt nothing but depressed this entire pregnancy and today has made it so much worse.