Since you have less than 2000 reputation on Stack Overflow, you do not have full edit privileges. When you try to edit a post, you should see the following notification:
You do not have edit privileges. Your edit will be placed in a queue until it is peer reviewed.
We welcome all constructive edits, but please make them substantial. Avoid trivial, tiny one-letter edits unless absolutely necessary.
Thus, the reason you aren't seeing your edits is probably because they were rejected by other users. And if you have too many edits rejected, you will be temporarily banned from suggesting any more edits. That's what the message you're getting now is telling you: you need to wait 7 days before you will be allowed to suggest any more edits.
However, retagging a question only requires 500 rep, so you have full privileges for that on SO. Your edits don't have to be approved by other users, and they show up immediately.