go into SETTINGS, then "general settings", look for "default thread subscription mode" option, and change it to "Do Not Subscribe" so you don't get the notification on every one that you post on. you'll have to subcribe individually to the ones you do want to then.
to find posts you've made or started, click on "MY PROFILE", and look on the left...."threads i started" and "threads i posted to"
it's all there