First of all, you're not a loser. It's human to want companionship and relationships.
You need to be able to tell the difference between when you are just flattered and happy someone likes you and when you are honestly truly interested. If someone likes you and you don't return those feelings, it's not fair to them that you play along.
And about expectaions... from what I've seen, where you "aim" for a person and a relationship really doesn't matter. There are many people who are complete opposites who make it together, also many people of different social classes, different ages, different family backgrouds, etc...
You said something about being "cut out for relationships" You may not be ready to be in a relationship right now. Just because you've had a few failed relationships doesn't make you inable to be in a realationship.