remembering my past and feeling empty/ depressed

i'm now alone.....the only support system i have my elderly mum and dad....and they live far from me...i live alone in a small one bedroom flat, living a lonely existence.....and when i think of the long ago past and all the people i knew, friends at school etc who i lost contact with....i feel doubly alone and isolated....abandoned almost...stuck in my own world.....i wish i knew where all the people i once knew are now and what they're doing...

what can i do now? i'm approaching mid 40s and never found a partner...i can't help but feel a little sorry for myself.