there are plugins to solve that, in your wp plugins area (where you add new plugin) do a search for "flood" plugins, install one of them, this should solve your problem.
when i comment on my own blog, i activate that plugin, once commenting is done, i deactivate it.
don't forget to deactivate you antispam plugins while doing comment posting on your own blog, and activate it once done.
that's how i handled same problem on my blog, i hope this will help you.