Okay I have a slightly different response to the others here - and my answer might not be the one for you - but it's what worked for me.
I was 30 and single and really, really down about it. People who say 'oh he'll turn up' are missing the point - it's lonely being single - and you endup feeling unlovable.
I decided (partly for other reasons too, such as being very anxious) to see a therapist - it was the best thing I have ever done. I looked back over my past and all the relationships I had had - why they didnt work out, why I felt unloveable - and I suddenly saw the reason I was single was really down to me and my own choices. That was hard to accept - and it's also complicated, I can't go into here the many ways in which I had limited my own life - and your own reasons will be personal.
I can't give you the answers here - but I have seen it with other friends who were single for long periods, there were often real reasons , based on their own family history - that left them choosing badly/ lacking in the confidence needed to be open to relationships/ or the confidence to let men know how they felt/ be happy once they did meet someone.
All the while, they are thinking, oh there is something wrong with me - and it's a vicious circle.
Just as an example - I have a friend who is lovely and very pretty but always single - I can see that she is so shy and reserved, she has spent years trying to hide it whenever she likes a man - so he won't know. She is hoping for a knight on shining armour - but not seeing that whenever there is a man she likes/ who likes her, she backs away. She actually can't see she is doing this and becomes more and more despondent.
Or - in my case - I was so desperate to meet someone, I would get into ridiculous relationships with awful men, that would be disastrous and short lived. AS soon as I saw this - and the whole complex web of my own choices, I calmed down, tried to be confident in myself and believe I would meet the right person - and I did.
So - we all have different ways of sabotaging our happiness - but sit down and make a list of your relationship patterns..(good book - Oliver James - They fuck you up - read it to learn how our family patterns affect our relationship choices) even if you think there is nothing there, have a real hard look at how you have behaved while trying to find men.
The sad truth is, if you lack confidence in yourself, you won't find the right person for you. Step one - build that confidence and believe in yourself.
6 months into the therapy, age 31, I met my soul mate - (having thought I would die alone and be eaten by cats!) and the therapist gave me the confidence in the early stages, not to blow it by being a nutter!
Final point - I dont agree that if you just sail on as normal mr right will turn up - I think you have to enjoy an active hunt! Instead of dating websites - choose new activities/ ways of spending your time where you know you will meet new people. Not just new men - but new friends.
Go to festivals with just one mate - talk to strangers - join a choir/ orchestra/ find a couple of single mates and go clubbing / go on adventure holidays / start cycling and join a cycling club - whatever, but if you set out to meet friends, develop your passions in life, the man will follow.
and...have some therapy!