I think I smell really bad
Why do you think that?
I smelled myself yesterday and nearly gagged.
Do you think you need to shower more, or do you have bad breath or something? Maybe if you just try to take better care of your hygiene; you'll smell better and feel healthier.
Then maybe I need to start using that body wash instead.
That might be a good idea, as long as you include it in an overall hygiene regimen.  But if you still have doubts, you should ask a trusted friend to be honest with you, as you might not even smell bad at all.