How do I live being single?

I haven’t been single in almost 5 years... I don’t know how to feel. How do i go to bed without telling someone I love them? How do i wake up knowing that there’s no one there for me when I do? What do I do when I crave love and affection and not have anyone to give it to me or for me to give it to? It scares the living shit out of me and it’s the only thing that’s keeping me from ending a relationship I’m unhappy in.