It's common (and sometimes necessary) to be condescending. So, make up for it by having an excess of goodwill. Give praise when you can, smile, try to be friendly, vocalize your self awareness etc.
When you realize you may have said something condesending, say "sorry, that may have come out wrong, I didn't mean it personally. Some people say I'm _____ but I don't mean to be". That's the kind of thing that won't necessarily make your coworkers think you aren't condescending, but they may still like you.
For example, it isn't uncommon for males to to be totally oblivious to the fact that they treat their female colleagues in a condescending fashion but not their male colleagues.
I really think you can turn this from something awkward to something positive with the right attitude.
If you cannot confront your critics, you cannot correct yourself if you're in the wrong. Also it will help you maneuver social situations better.
To be or not to be condescending - that is a situation that needs to be understood, before you actually act it.
That said, clumsy help is worse than none. If your manager is not particularly political then you can disregard that advice entirely.
Life. Sometimes people won't like you.