Nope. Not at all.
I am currently on a roll and I am getting an AVERAGE knockback rate of about 5 submissions before acceptance (some more, some less, but never first time). I take it as part of the process to write, listen to the comments and redraft. Though it hurts and is annoying, the papers DO get better because of this.
I am now in a position where I am "signing off" papers from the other team members before they submit to journals. One of the other two postdocs have only published 1 article since completing his thesis, and has had this second paper (from his thesis) rejected 8 times already. Its good work, but its very niche, so he has to try lots of places.
My advice is to sit down with someone objective and go through it. Is the work good, or are you being knocked back because of the natural rejection rate. Think of it like dating, you expect to go on lots of dates before you find your spouse right?