I don't think i like my new (sales) job is for me... Should I leave?

I feel that if you are good at convincing people then this job is for you. But, if you cannot easily convince them or make them interested in your talk, you must leave this field and get back to science. You do not start enjoying anything that needs efforts. No matter which field you join, you will feel you will not be able to do it. You have to make efforts and if you are good at it after some time you will begin enjoying it!