Will masturbating once every two weeks cause any hair loss or recedibg hair line?

No: I've seen the internet claims that enjoying your body causes baldness. A few of the cults are promoting it to frighten young men. The whole business about testosterone metabolites is made up. Almost all young men need to enjoy their bodies to stay comfortable and prepare them for adult roles. Don't torment yourself like this. Embrace being a grown man. Think about the girl you'll marry. Cheers.