How do you keep hope?

I've wanted a baby for my whole marriage (13 years) -- my whole life really. At first we waited a couple of years to start trying to be "responsible" (ha! What a huge mistake). Then my pcos, and then my husband developing health issues prevented us from conceiving. Now we are finally actively trying again for the last 5 months. I'll start clomid or femara next month. 
Last year my best friend tried for three months and got pregnant with her second son. Two days ago my sister (we are very close) found out she got preg on the pill (obviously not yet trying to though they were about to try). 
My mom got preg twice without trying and twice on the first try. 
The more I look around and think about everyone I know, the more I feel like I'm kidding myself and that this is never going to happen. 
I don't want to lose hope. How do you stay hopeful?