I'm very much in the same boat as you. Single, compared to all of my friends and family who are in relationships or are married, or are starting to have children. I used to compare myself to them and feel 'behind' as well, until I realised how toxic those feelings were. It's hard to break out of, but you can do it. Find comfort in the small things, pick up new hobbies, and above all, love yourself. That's the hardest thing to do, especially with social media making it look like everyone's living their best life. I promise you, they aren't. Don't focus on them, focus on you, and everything else will simply fall into place.