How can I find a person (source) who is spreading roumer about me. People talk at my back and could not cooperate or give any respect and support to me. I feel very lonely and friends are no more friends as they feel I'm a bad character person
Should I ask people directly what they think about me and who told them so

The only solution to a rumor is to ignore them. No one will want to gossip about you if it doesn't bother you.

Also if you're previous friends are no longer your friends because they think you're a bad character then ask yourself "I'm I a bad character/influence?"

Do you do things that others disapprove of?
Do you drink a lot?
Smoke A lot?
Swear a lot?
Beat your spouse etc... the list could go on forever but you get my point, is there a reason your friends are no longet your friends?

If not the rockerchick is right, the best way to handle a rumor is a deaf ear. The person starting these rumors won't stop just because you don't lik it they'll probably get more fired up!