Just make it sure all your comments is connected to the topic and make it sure the thread you are commented has have sense and if you making a thread make it sure it is in the right topic and you're not making a thread too fast. Aside that your messages will not decreased anymore.
From what I'm looking at, you have a certain amount of warnings.sometimes, the topics have to be deleted, so if you have commented on that topic, it will be deleted in your comment.Obey the forum rules that I recommend you can give Do not comment on every topic especially trash topic.