I really do believe that there is someone in the world for everyone. That includes you. Look around you. All kinds of people find love. It doesn’t always have to do with looks or personality.
I don’t think you have to try “harder”. I do think you may have to try “differently”. That means getting some feedback about how you are seen by others and getting some guidance about how to change your behavior so you are more successful.
My best suggestion is that you seek out some group therapy. Under the guidance of a mental health professional, group members get direct feedback from each other about their behavior as well as opportunities to try out different ways of relating.
Don’t be so sure that you can’t afford help. Group therapy tends to be less expensive than individual therapy. Contact a mental health center to find out what is available. You may also be able to find a free singles support group in your city.
I wish you well.