Don't be too hard on yourself. Everybody has bad days. You just have to pick yourself back up and remind yourself that it's not forever.
There's no one right time for people to meet "the one". Some people find somebody at a young age and live a good life together. Some it takes a while longer. Some think they've found the right one at a young age, but that end up wasting years of their life being miserable with that person. Others don't find somebody until much later, but say it was well worth the wait. It's just a different convoluted path for everyone.
If having a lasting relationship is important to you and you're willing to make it work, you'll find someone. Don't let yourself get too discouraged. Just try to have fun meeting people, and let it lead where it will. It often happens when you least expect it.
“This planet has - or rather had - a problem, which was this: most of the people living on it were unhappy for pretty much of the time. Many solutions were suggested for this problem, but most of these were largely concerned with the movement of small green pieces of paper, which was odd because on the whole it wasn't the small green pieces of paper that were unhappy.” ― Douglas Adams, The Hitchhiker's Guide to the Galaxy