I'm just so lost

I'm almost 30 and have watched all of my friends surpass me, with careers, families, love and happiness. I finally found someone I thought I'd spend my life with, but she left in the summer and left me with such an emptiness in my heart. All of my free time is just dark and lonely now. I crave any kind of meaning in my life, but I can't find a job, can't hold onto love, have nobody to share my time with, and have no reason to keep going.