Can my commander restrict me to post?

Restrictions are not imposed for shits and giggles.
The key word I hear in your limited explanation is "currently".
What I get from that is that there was in fact an infraction of some sort, and you are receiving an informal punishment.

If I have accurately deduced the situation, take the restriction (assuming it is not in perpetuity) and shut up. You need to earn your leader's trust back.

No, but in any case you’re asking the wrong folks.. Go seek assistance at legal on post. Nothing ANYONE says here makes a difference to your commander.
And there are always three sides to a story, any response here is to only one side.

As has been said, there is more to this than what you stated. I'm not sure what the size of the command is or the level of the Commander is, but, I have found in most circumstances, you are far better to take the "unofficial" restriction and leave it go.